It turned out that we failed to emit proper symbol stubs on non-x86/darwin for ages (we emitted a reference to a stub, but no stub was emitted). The code inside x86-32/macho target objfile lowering should actually be the generic one - move it there.

This (I really, really hope) should fix EH issues on ppc/darwin
and arm/darwin.

llvm-svn: 96755