[lld-macho] Ignore local personality symbols if non-local with the same...

    [lld-macho] Ignore local personality symbols if non-local with the same name exisst,  to avoid "too many personalities" error.

    Sometimes people intentionally re-define a dylib personlity symbol as a local defined symbol as a workaround to a ld -r bug.
    As a result, we could see "too many personalities" to encode. This patch tries to handle this case by ignoring the local symbols entirely.

    Differential Revision: https://reviews.llvm.org/D107533