Revert r230921, "Revert some changes that were made to fix PR20680.", for now.

It caused a failure on clang/test/Misc/backend-optimization-failure.cpp .

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230929 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed