Upgrade ext-toolchain GCC ports to GCC 6.4.0
This is the latest supported release in GCC 6.x series.
Drop aarch64 support patch - it has been committed upstream.
Enable ifunc suppport by default.
Reviewed by: bapt (update part)
Differential Revision: https://reviews.freebsd.org/D13602
Mark the gcc crosscompiler ports as broken on various tier-2 archs.
Unfortunately neither the maintainer or I have time at the moment
to chase down all of these failures. The "fails to package" ones
ought to be fairly easy to fix.
Discussed with: maintainer
Add a cross version of gcc minimalistic and suitable enough to cross build world
Current targets: powerpc64 sparc64
Note that gcc 4.9.1 never heard of mips on freebsd neither of arm on freebsd
Note that this does not yet includes the freebsd extensions meaning it cannot
cross build the kernel yet