[Bug go/68562] morestack misaligns stack on x86_64

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68562

--- Comment #8 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
markus@x4 gcc_build_dir % ../gcc/configure --disable-libsanitizer
--enable-valgrind-annotations --disable-bootstrap --disable-libstdcxx-pch
--disable-libvtv --disable-libitm --disable-libcilkrts --disable-libssp
--disable-libgomp --disable-werror --disable-multilib
--enable-languages=c,c++,go
markus@x4 gcc_build_dir % make -j4