Remove trailing whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189178 91177308-0d34-0410-b5e6-96231b3b80d8
Check if in set on insertion instead of separately

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189179 91177308-0d34-0410-b5e6-96231b3b80d8