gcc: Include libgcc.a on those architectures that need it
Right now these are arm, hppa, microblaze, powerpc, sh and xtensa.
So we just try to grep for it to figure out if it is needed.
Signed-off-by: Harald Geyer <harald@ccbib.org>
Signed-off-by: Christian Beier <dontmind@freeshell.org>