Instead, walk the obj symbol list in parallel to find the GV. This shouldn't
change anything on ELF where global symbols are not mangled, but it is a step
toward supporting other object formats.
Gold itself is ELF only, but bfd ld supports COFF and the logic in the gold
plugin could be reused on lld.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223780 91177308-0d34-0410-b5e6-96231b3b80d8