Wrap to 80 columns, no behavior change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@215776 91177308-0d34-0410-b5e6-96231b3b80d8
Add a RAII class for saving and restoring instantiations and uses. No behavior change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@215780 91177308-0d34-0410-b5e6-96231b3b80d8