Fix missing -*- C++ -*-s

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187758 91177308-0d34-0410-b5e6-96231b3b80d8
Add some comment to LTOCodeGenerator class

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187761 91177308-0d34-0410-b5e6-96231b3b80d8