Restore Zhongxing's commits r97122 r97127 r97129 r97131 which were reverted due to a Clang-on-Clang failure

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97162 91177308-0d34-0410-b5e6-96231b3b80d8
8 files changed