Log message:
bmake: Use 64 bit off_t on SunOS

Fixes bmake not finding files (e.g. .include) on Illumos wiht 32 bit
ABI.

See also: https://www.illumos.org/issues/9508

Log message:
bmake: Update to 20200524.

This should help bootstrap on older platforms, such as IRIX with
the mipspro compiler.

2020-05-24  Simon J Gerraty  <sjg@beast.crufty.net>

	* configure.in: add AC_PROG_CC_C99 for mipspro compiler
	* dirname.c: remove include of namespace.h

Log message:
bmake: Update to 20200517

2020-05-17  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200517
	Merge with NetBSD make, pick up
	o modified dollar tests to avoid shell dependencies
	o new tests for .INCLUDEFROM

2020-05-16  Simon J Gerraty  <sjg@beast.crufty.net>

	* unit-tests/dollar.mk: tweak  '1 dollar literal' test
	to not depend so much on shell behavior

2020-05-10  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200510
	Merge with NetBSD make, pick up
	o unit test for dollar handling

2020-05-06  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200506
	Merge with NetBSD make, pick up
	o str.c: empty string does not match % pattern
	  plus unit-test changes

2020-05-04  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200504
	May the 4th be with you
	Merge with NetBSD make, pick up
	o var.c: import handling of old sysV style modifier using '%'
	o str.c: refactor brk_string
	o unit-tests: add test case for lazy conditions

2020-04-18  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200418

	* configure.in: use_makefile=no for cygwin et al.
	case insensitive filesystems just don't work if both
	makefile and Makefile exist.
	NOTE: bmake does not support cygwin and likely never will,
	but if brave souls want to try it - help them out.

2020-04-02  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200402
	Merge with NetBSD make, pick up
	o meta.c: meta_oodate, CHECK_VALID_META is too aggressive for CMD
	  a blank command is perfectly valid.

2020-03-30  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200330
	Merge with NetBSD make, pick up
	o make.h: extern debug_file

2020-03-18  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200318
	Merge with NetBSD make, pick up
	o meta.c: meta_oodate, check for corrupted meta file
	  earlier and more often.

2020-02-20  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200220

2020-02-19  Simon J Gerraty  <sjg@beast.crufty.net>

	* boot-strap: unset MAKEFLAGS

2020-02-12  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION (_MAKE_VERSION): 20200212
	* meta.c: meta_compat_parent check for USE_FILEMON
	  patch from Soeren Tempel

2020-02-05  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20200205
	Merge with NetBSD make, pick up
	o meta.c: fix compat mode, need to call meta_job_output()
	o job.c: extra fds for meta mode not needed if using filemon_dev

2020-01-22  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20200122
	Merge with NetBSD make, pick up
	o meta.c: avoid passing NULL to filemon_*() when meta_needed()
	  returns FALSE.

2020-01-21  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20200121
	Merge with NetBSD make, pick up
	o filemon/filemon_{dev,ktrace}.c: allow selection of
	  filemon implementation.  filemon_dev.c uses the kernel module
	  while filemon_ktrace.c leverages the fktrace api available in
	  NetBSD.  filemon_ktrace.c can hopefully form the basis for
	  adding support for other tracing mechanisms such as strace on
	  Linux.
	o meta.c: when target is out-of-date per normal make rules
	  record value of .OODATE in meta file.

2019-09-26  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20190926
	  Merge with NetBSD make, pick up
	  o parse.c: don't pass NULL to realpath(3)
	    some versions cannot handle it.

2019-04-09  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20190409
	  Merge with NetBSD make, pick up
	  o parse.c: ParseDoDependency: free paths rather than assert

2018-12-22  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20181222

	* configure.in: add --without-makefile to avoid generating
	  makefile and make-bootstrap.sh

	* include Makefile.inc if it exists

	* Use Makefile and Makefile.config.in in unit-tests
	  so we can use just: make obj && make && make test
	  when bmake is already available.
	  We add --without-makefile to CONFIGURE_ARGS in this case.

	* tweak bsd.after-import.mk (captures Makefile.config etc
	  after import to FreeBSD for example) to cope with all the above.

2018-12-21  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20181221
	  Merge with NetBSD make, pick up
	  o parse.c: ParseVErrorInternal use .PARSEDIR
	    and apply if relative, and then use .PARSEFILE
	    for consistent result.

2018-12-20  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20181220
	  Merge with NetBSD make, pick up
	  o parse.c: ParseVErrorInternal use .CURDIR if .PARSEDIR
	    is relative
	  o var.c: avoid SEGFAULT in .unexport-env
	    when MAKELEVEL is not set

2018-12-16  Simon J Gerraty  <sjg@beast.crufty.net>

	* VERSION: 20181216
	  Merge with NetBSD make, pick up
	  o fix for unit-tests/varquote.mk on Debian

2018-09-21  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20180919
	  Merge with NetBSD make, pick up
	  o var.c: add :q
	  o dir.c: cleanup caching of stats

2018-09-21  Simon J Gerraty  <sjg@beast.crufty.net>

	* Makefile.config.in: use += where it makes sense.

2018-05-12  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20180512
	  Merge with NetBSD make, pick up
	  o job.c: skip polling job token pipe

2018-04-05  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20180405
	  Merge with NetBSD make, pick up
	  o parse.c: be more cautious about detecting depenency line
	    rather than sysV style include.

2018-02-22  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20180222
	  Merge with NetBSD make, pick up
	  o parse.c: avoid calling sysconf for every call to loadfile

2018-02-18  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20180218
	  Merge with NetBSD make, pick up
	  o var.c: Var_Set handle NULL value anytime.

2018-02-12  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20180212
	  Merge with NetBSD make, pick up
	  o parse.c: do not treat .info as warning with -W

2017-12-07  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20171207
	  Merge with NetBSD make, pick up
	  o var.c: Var_Append use Var_Set if var not previously set
	    so that VAR_CMD is handled correctly.
	    Add a suitable unit-test.

2017-11-26  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION (_MAKE_VERSION): 20171126

	* aclocal.m4: use AC_LINK_IFELSE for AC_C___ATTRIBUTE__
	  since AC_TRY_COMPILE puts input inside main()
	  which upsets modern compilers.

2017-11-18  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20171118
	  Merge with NetBSD make, pick up
	  o var.c: do not append to variable set on command line
	    add unit-test to catch this.

2017-10-28  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20171028
	  Merge with NetBSD make, pick up
	  o main.c: ignore empty MAKEOBJDIR

	* Makefile.config.in:
	  make @prefix@ @machine*@ and @default_sys_path@ defaults.

2017-10-05  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION: 20171005

	* unit-tests/dotwait.mk: redirect stderr through pipe for more
	  consistent result on some platforms.

2017-08-13  Simon J. Gerraty  <sjg@bad.crufty.net>

	* machine.sh: entry for AIX

2017-08-12  Simon J. Gerraty  <sjg@bad.crufty.net>

	* VERSION (_MAKE_VERSION): Move the setting of _MAKE_VERSION
	  to a file that can be included by configure as well as make.
	  This allows configure to set set _MAKE_VERSION in make-bootstrap.sh

2017-08-10  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170810
	  Merge with NetBSD make, pick up
	  o meta.c: if target is in subdir we only need subdir name in
	    meta_name.

2017-07-20  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170720
	  Merge with NetBSD make, pick up
	  o compat.c: pass SIGINT etc onto child and wait for it to exit
	    before we self-terminate.

2017-07-11  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170711
	  forgot to update after merge on 20170708 ;-)
	  o main.c: refactor to reduce size of main function.
	    add -v option to always fully expand values.
	  o meta.c: ensure command output in meta file has ending newline
	    even when filemon not being used.
	    When matching ${.MAKE.META.IGNORE_PATTERNS} do not use
	    pathname via ':L' since any ':' in pathname breaks that.
	    Instead set a '${.p.}' to pathname in the target context and
	    use that.

2017-05-10  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170510
	  Merge with NetBSD make, pick up
	  o main.c: Main_SetObjdir: ensure buf2 is in scope

2017-05-08  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170505
	  see mk/ChangeLog

2017-05-05  Simon J. Gerraty  <sjg@bad.crufty.net>

	* parse.c: not everyone has stdint.h

2017-05-01  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170501
	  see mk/ChangeLog

2017-04-21  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170421
	  Merge with NetBSD make, pick up
	  o str.c: Str_Match: fix closure tests for [^] and add unit-test.

2017-04-20  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170420
	  Merge with NetBSD make, pick up
	  o main.c: only use -C arg "as is" if it contains no
	    relative component.

2017-04-18  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170418
	  Merge with NetBSD make, pick up
	  o main.c: fix Main_SetObjdir() for relative paths (eg obj).

2017-04-17  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170417
	  Merge with NetBSD make, pick up
	  o fixes a number of coverity complaints
	    - check return value of fseek, fcntl
	    - plug memory leak in Dir_FindFile, Var_LoopExpand,
	      JobPrintCommand, ParseTraditionalInclude
	    - use bmake_malloc() where NULL is not tollerated
	    - use MAKE_ATTR_UNUSED rather that kludges like
	      return(unused ? 0 : 0)
	    - use purge_cached_realpaths() rather than abuse cached_realpath()

2017-04-13  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170413
	  Merge with NetBSD make, pick up
	  o main.c: when setting .OBJDIR ignore '$' in paths.

	* job.c: use MALLOC_OPTIONS to set malloc_options.

2017-04-11  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170411
	  Merge with NetBSD make, pick up
	  o str.c: Str_Match: allow [^a-z] to behave as expected.

2017-03-26  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170326
	  Merge with NetBSD make, pick up
	  o main.c: purge relative paths from realpath cache when .OBJDIR
	    is changed.

2017-03-11  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170311
	  Merge with NetBSD make, pick up
          o main.c: only use -C arg "as is" if it starts with '/'.

2017-03-01  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170301
	  Merge with NetBSD make, pick up
	  o main.c: use -C arg "as is" rather than getcwd()
	    if they identify the same directory.
	  o parse.c: ensure loadfile buffer is \n terminated in non-mmap case

2017-02-01  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170201
	  Merge with NetBSD make, pick up
	  o var.c: allow :_=var and avoid use of special context.

2017-01-30  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170130
	  Merge with NetBSD make, pick up
	  o var.c: add :range and :_
	  o main.c: partially initialize Dir_* before MainParseArgs()
	    can be called.
	    If -V, skip Main_ExportMAKEFLAGS()

2017-01-14  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20170114
	  Merge with NetBSD make, pick up
	  o var.c: allow specifying the utc value used by :{gm,local}time

2016-12-12  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20161212
	  Merge with NetBSD make, pick up
          o main.c: look for obj.${MACHINE}-${MACHINE_ARCH} too.

2016-12-09  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20161209
	  Merge with NetBSD make, pick up
	  o main.c: cleanup setting of .OBJDIR
	  o parse.c: avoid coredump from (var)=val

2016-11-26  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20161126
	  Merge with NetBSD make, pick up
	  o make.c: Make_OODate: report src node name if path not set

2016-09-26  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160926
	  Merge with NetBSD make, pick up
	  o support for .DELETE_ON_ERROR: (remove targets that fail)

2016-09-26  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile MAN: tweak .Dt to match ${PROG}

2016-08-18  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160818
	  its a neater number; pick up whitespace fixes to man page.

2016-08-17  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160817
	  Merge with NetBSD make, pick up
	  o meta.c: move handling of .MAKE.META.IGNORE_* to meta_ignore()
	    so we can call it before adding entries to missingFiles.
	    Thus we do not track files we have been told to ignore.

2016-08-15  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160815
	  Merge with NetBSD make, pick up
	  o meta_oodate: apply .MAKE.META.IGNORE_FILTER (if defined) to
	    pathnames, and skip if the expansion is empty.
	    Useful for dirdeps.mk when checking DIRDEPS_CACHE.

2016-08-12  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160812
	  Merge with NetBSD make, pick up
	  o meta.c: remove all missingFiles entries that match a deleted
	    dir.
	  o main.c: set .ERROR_CMD if possible.

2016-06-06  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160606
	  Merge with NetBSD make, pick up
	  o dir.c: extend mtimes cache to others via cached_stat()

2016-06-04  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160604
	  Merge with NetBSD make, pick up
	  o meta.c: missing filemon data is only relevant if we read a
	    meta file.
	    Also do not return oodate for a missing metafile if gn->path
	    points to .CURDIR

2016-06-02  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160602
	  Merge with NetBSD make, pick up
	  o cached_realpath(): avoid hitting filesystem more than necessary.
	  o meta.c: refactor need_meta decision, add knobs for
	    missing meta file and filemon data wrt out-of-datedness.

2016-05-28  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160528

	* boot-strap, make-bootstrap.sh.in: Makefile now uses _MAKE_VERSION

2016-05-12  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160512
	  Merge with NetBSD make, pick up
	  o meta.c: ignore paths that match .MAKE.META.IGNORE_PATTERNS
	    this is useful for gcov builds.
	  o propagate errors from filemon(4).

2016-05-09  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160509
	  Merge with NetBSD make, pick up
	  o remove use of non-standard types u_int etc.
	  o meta.c: apply realpath() before matching against metaIgnorePaths

2016-04-04  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160404
	  Merge with NetBSD make, pick up
	  o allow makefile to set .MAKE.JOBS

	* Makefile (PROG_NAME): use ${_MAKE_VERSION}

2016-03-15  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): 20160315
	  Merge with NetBSD make, pick up
	  o fix handling of archive members

2016-03-13  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (_MAKE_VERSION): rename variable to avoid interference
	  with checks for ${MAKE_VERSION}

2016-03-10  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20160310
	  Merge with NetBSD make, pick up
	  o meta.c: treat missing Read file same as Write, incase we Delete it.

2016-03-07  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20160307
	  Merge with NetBSD make, pick up
	  o var.c: fix :ts\nnn to be octal by default.
	  o meta.c: meta_finish() to cleanup memory.

2016-02-26  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20160226
	  Merge with NetBSD make, pick up
	  o meta.c: allow meta file for makeDepend if makefiles want it.

2016-02-19  Simon J. Gerraty  <sjg@bad.crufty.net>

	* var.c: default .MAKE.SAVE_DOLLARS to FALSE
	  for backwards compatability.

	* Makefile (MAKE_VERSION): 20160220
	  Merge with NetBSD make, pick up
	  o var.c: add knob to control handling of '$$' in :=

2016-02-18  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20160218
	  Merge with NetBSD make, pick up
	  o var.c: add .export-literal allows us to fix sys.clean-env.mk
	    post the changes to Var_Subst.
	    Var_Subst now takes flags, and does not consume '$$' in :=

2016-02-17  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20160217
	  Merge with NetBSD make, pick up
	  o var.c: preserve '$$' in :=
	  o parse.c: add .dinclude for handling included
	    makefile like .depend

2015-12-20  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20151220
	  Merge with NetBSD make, pick up
	  o suff.c: re-initialize suffNull when clearing suffixes.

2015-12-01  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20151201
	  Merge with NetBSD make, pick up
	  o cond.c: CondCvtArg: avoid access beyond end of empty buffer.
	  o meta.c: meta_oodate: use lstat(2) for checking link target
	    in case it is a symlink.
	  o var.c: avoid calling brk_string and Var_Export1 with empty
	    strings.

2015-11-26  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20151126
	  Merge with NetBSD make, pick up
	  o parse.c: ParseTrackInput don't access beyond
	    end of old value.

2015-10-22  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20151022

	* Add support for BSD/OS which lacks inttypes.h
	  and really needs sys/param.h for sys/sysctl.h
	  also 'type' is not a shell builtin.

	* var.c: eliminate uint32_t and need for inttypes.h

	* main.c: PrintOnError flush stdout before run .ERROR

	* parse.c: cope with _SC_PAGESIZE not being defined.

2015-10-20  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20151020
	  Merge with NetBSD make, pick up
	  o var.c: fix uninitialized var

2015-10-12  Simon J. Gerraty  <sjg@bad.crufty.net>

	* var.c: the conditional expressions used with ':?' can be
	expensive, if already discarding do not evaluate or expand
	anything.

2015-10-10  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20151010
	  Merge with NetBSD make, pick up
	  o Add Boolean wantit flag to Var_Subst and Var_Parse
	    when FALSE we know we are discarding the result and can
	    skip operations like Cmd_Exec.

2015-10-09  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20151009
	  Merge with NetBSD make, pick up
	  o var.c: don't check for NULL before free()
	  o meta.c: meta_oodate, do not hard code ignore of makeDependfile

2015-09-10  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20150910
	  Merge with NetBSD make, pick up
	  o main.c: with -w print Enter/Leaving messages for objdir too
	    if necessary.
	  o centralize shell metachar handling

	* FILES: add metachar.[ch]

2015-06-06  Simon J. Gerraty  <sjg@bad.crufty.net>

	* Makefile (MAKE_VERSION): 20150606
	  Merge with NetBSD make, pick up
	  o make.1: document .OBJDIR target

Log message:
Import bmake-

Log message:
On Minix3 the call to read returns EAGAIN (-1) and causes the build to break.
Skip punting on Minix3 as workaround for now, change via sjg@

Log message:
Set default malloc_options iff NetBSD. Other platforms that don't
support the same options may make noise about that, such as OpenBSD.
Suggested by joerg@.

Log message:
Avoid warnings about implicit declaration of function 'ffs'

Besides addressing these warnings, this patch should not modify the resulting
binary in any way. There should be no need to re-compile or bump any version or
revision.

Compile-tested on NetBSD/amd64. "Should be ok" joerg@

Log message:
Fix a problem with MAKE_VERSION being undefined on case-insentive filesystems.

On case-insensitive filesystems such as MacOS, two files (Makefile and makefile,
which is created by configure from makefile.in) collide.  Only the former
defines MAKE_VERSION, but it is replaced by the latter.  Consequently,
MAKE_VERSION is defined as an empty string on these systems.  This patch is
the result of a discussion on tech-pkg (see the thread following
http://mail-index.netbsd.org/tech-pkg/2017/08/13/msg018629.html) and is
based upon code incorporated into bmake v20170812.

Log message:
Use OPSYSVARS.

Log message:
Attempt to bring sanity to how ABI and MACHINE_ARCH are set.

Previously there were at least 5 different ways MACHINE_ARCH could be set,
some statically and some at run time, and in many cases these settings
differed, leading to issues at pkg_add time where there was conflict
between the setting encoded into the package and that used by pkg_install.

Instead, move to a single source of truth where the correct value based on
the host and the chosen (or default) ABI is determined in the bootstrap
script.  The value can still be overridden in mk.conf if necessary, e.g.
for cross-compiling.

ABI is now set by default and if unset a default is calculated based on
MACHINE_ARCH.  This fixes some OS, e.g. Linux, where the wrong default was
previously chosen.

As a result of the refactoring there is no need for LOWER_ARCH, with
references to it replaced by MACHINE_ARCH.  SPARC_TARGET_ARCH is also
removed.