FileCheck-ify some clang grep tests that use double quotes

The escaping interaction between Python and grep doesn't work on my
system.  This change fixes the tests for me.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179214 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed