Summary:
Fix a case when "FileCheck --check-prefix=CHECK --check-prefix=CHECKER"
would silently ignore check-lines of the form:
CHECKER: foo
Reviewers: dsanders
Reviewed By: dsanders
CC: llvm-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2168
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194577 91177308-0d34-0410-b5e6-96231b3b80d8