Actually call FileCheck in tests

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201491 91177308-0d34-0410-b5e6-96231b3b80d8
Add extra CHECK prefix to tests with explicit prefix

These tests mistakenly assume that CHECK is still available even if an
explicit prefix is specified.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201492 91177308-0d34-0410-b5e6-96231b3b80d8
Fix more broken CHECK lines

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201493 91177308-0d34-0410-b5e6-96231b3b80d8