startswith_lower is ocassionally useful and I think worth adding. endwith_lower is added for completeness. Differential Revision: http://llvm-reviews.chandlerc.com/D2041 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193706 91177308-0d34-0410-b5e6-96231b3b80d8