sys-devel/gcc: bump 4.9.4 patch set up to 1.2, bug #629502

sys-devel/gcc: bump 4.9.4 patch set up to 1.2, bug #629502

Patchset contains the following new patches (picked as-is from 5.4.0):
- 94_all_compatibility_fix_with_perl_5.26.patch: regex tweak for perl-5.26
- 95_all_asan-signal_h.patch: add missing '<signal.h>' header
- 96_all_ucontext-to-ucontext_t.patch: change 'struct ucontext' to 'ucontext_t'
- 97_all_no-sigaltstack.patch: remove 'sigaltstack' usage
to fix gcc-4.9.4 build failure against glibc-2.26.

I've deleted 4.9.4-r1 as it contained single build-time fix for perl-5.26.

Closes: https://bugs.gentoo.org/629502
Closes: https://bugs.gentoo.org/620164
Package-Manager: Portage-2.3.12, Repoman-2.3.4