Log Message:
Make this ancient mule2 build and work (at least start up) on NetBSD/i386 7.1.

- pull unexelf.c from newer emacs to fix coredump on dump-charset
- in s/netbsd.h use terminfo rather than obsolete termcap that causes SIGSEGV
- also link temacs with "-Wl,-znocombreloc" for X toolkit as emacs22 did
  XXX: this should be into configure
- specify -fno-builtin-malloc to avoid unexpected gcc's optimization
  and remove hacks in alloc.c
- also specify -fno-strict-aliasing for sanity against 90's files