glibc parallel builds broken

[David Miller]

Siddhesh, your change tonight broke parallel builds for me.

The problem is that nothing makes sure that gnu/lib-names.h is
generated before files that include it are built.

As a result, what happens is that it ends up including the system
/usr/include/gnu/lib-names.h header which doesn't have a define for
LIBGCC_S_SO

Please add appropriate dependencies into the makefiles and whatever
else might be necessary to fix this.

Thank you.