We were creating a weak external that tried to reference a static symbol. That
would always fail to link with link.exe.
We now create an external symbol in the same position as the local and refer
to that. This works with link.exe and matches what gas does.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270906 91177308-0d34-0410-b5e6-96231b3b80d8
