gcc: fix exceptions handling for ada with mingw32
gcc: fix exceptions handling for ada with mingw32

At least with mingw32 + dwarf-2 exceptions there can only be one libgcc in
process, or exceptions will no longer work. Since some of the gcc deps are
linked dynamically like gmp/zlib/zstd and those pull in libgcc we can't
allow libgcc to be linked statically. The default is "-static-libstdc++
-static-libgcc" for both, so we drop "-static-libgcc" here.

See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105507#c3

oroppas/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,fabiangreffrath/MINGW-packages,oroppas/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages,Alexpux/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,oroppas/MINGW-packages,Alexpux/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,fabiangreffrath/MINGW-packages,stahta01/MINGW-packages,stahta01/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,oroppas/MINGW-packages,stahta01/MINGW-packages,stahta01/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,Alexpux/MINGW-packages,fabiangreffrath/MINGW-packages,fabiangreffrath/MINGW-packages,oroppas/MINGW-packages,Alexpux/MINGW-packages,Alexpux/MINGW-packages,Alexpux/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,fabiangreffrath/MINGW-packages,oroppas/MINGW-packages,oscarfv/MINGW-packages,fabiangreffrath/MINGW-packages,JPeterMugaas/MINGW-packages