toolchain: introduce BR2_TOOLCHAIN_HAS_GCC_BUG_83143

toolchain: introduce BR2_TOOLCHAIN_HAS_GCC_BUG_83143

ruby package fails to build for the SH4 architecture with optimization
enabled with gcc = 9.3.0:
http://autobuild.buildroot.net/results/f57/f5742e7fb6e8142bcdb53b7f4f5e9c1bea3558cd/

It's already been reported upstream:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83143

Anyway let's assume all SuperH(BR2_sh) have this bug according to:
http://lists.busybox.net/pipermail/buildroot/2021-August/621906.html

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>