Reapply r185601 with a fix for the cmake build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185605 91177308-0d34-0410-b5e6-96231b3b80d8
Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185606 91177308-0d34-0410-b5e6-96231b3b80d8
Add a space between closing template '>' to unbreak build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185607 91177308-0d34-0410-b5e6-96231b3b80d8