Added comments from Andrew Kaylor.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193033 91177308-0d34-0410-b5e6-96231b3b80d8
Avoid duplicate search by reusing the iterator.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193034 91177308-0d34-0410-b5e6-96231b3b80d8