Log message:
lang/gcc6, lang/gcc7: Make these build with newer gcc.

Otherwise libgomp has some -Wattributes errors.

Log message:
lang/gcc*: Set CC_FOR_BUILD and CXX_FOR_BUILD if cross-compiling.

Verified gcc6 and gcc7 cross-compile on NetBSD, at least if the
gcc-fortran option is disabled.  gcc8 and gcc9 have trouble because
of python (why do these have a full dependency on python?); gcc10 and
gcc12 are missing gcc/config/mips/netbsd64.h; gcc12 and gcc13 have a
cross-compile bug with missing __LIBGCC_*__ macros -- but in any
case, setting CC_FOR_BUILD and CXX_FOR_BUILD is obviously necessary
for cross-compilation.  Conditional on USE_CROSS_COMPILE, so no harm
to native builds.

Log message:
Ignore unreadable directories when looking for libgcc_s.so

Log message:
*: recursive bump for perl 5.36

Log message:
gcc6: workaround: get this at least building by disabling RELRO

Log message:
gcc8: deconditionalize CHECK_RELRO_SKIP

as hinted by mef's recent bulk build, it appears to be more complicated
than simply a matter of bootstrapping

Log message:
gcc6: use BLAKE2s

Log message:
lang/gcc*: skip some RELRO checks when --disable-boostrap

This relates to the case when GCC is built using clang host CC. In that
case the runtime libraries are not built with RELRO for some reason.

for the gcc*-libs/ packages, mark them as RELRO_SUPPORTED=no unconditionally.
RELRO status depends on how the parent gcc package was built so we don't
need nor care about the RELRO status here.

Log message:
lang: Remove SHA1 hashes for distfiles

Log message:
Prune gcc34, gcc44.