Now reportUndefined only has to look at Config->UnresolvedSymbols and
the symbol. getUnresolvedSymbolOption does all the hard work of
mapping options like -shared and -z defs to one of the
UnresolvedPolicy enum entries.
The critical fix is that now "-z defs --warn-unresolved-symbols" only
warns.
llvm-svn: 293290
Rafael Espindola