Fix typos "metatadata" -> "metadata" in the LangRef.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184426 91177308-0d34-0410-b5e6-96231b3b80d8
Remove MSan hack that is no longer needed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184428 91177308-0d34-0410-b5e6-96231b3b80d8