AsmParser: Remove unused version of ParseMDNodeID()

Merge the two versions of `ParseMDNodeID()` now that no one needs
special forward references.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225699 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed