Use FileCheck instead of grep. Change by Sonam.

Differential Revision: http://reviews.llvm.org/D6432



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222876 91177308-0d34-0410-b5e6-96231b3b80d8
Revert "Peephole optimization in switch table lookup: reuse the guarding table comparison if possible."

It is breaking the clang bootstrag.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222877 91177308-0d34-0410-b5e6-96231b3b80d8