Silencing a *lot* of -Wsign-compare warnings; NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224194 91177308-0d34-0410-b5e6-96231b3b80d8
Silencing a -Wsign-compare warning; NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224195 91177308-0d34-0410-b5e6-96231b3b80d8