[MachO][TLOF] Add support for local symbols in the indirect symbol table

On 32-bit archs, before, we would assume that an indirect symbol will
never have local linkage. This can lead to miscompiles where the
symbol's value would be 0 and the linker would use that value, because
the indirect symbol table would contain the value
`INDIRECT_SYMBOL_LOCAL` for that specific symbol.

Differential Revision: https://reviews.llvm.org/D55573

llvm-svn: 349060