Summary:
Lift some common code used by multiple checkers.
This function is also used by checkers that are coming.
It is quite common for a checker to parse a list of names.
Reviewers: alexfh
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D19846
git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@269065 91177308-0d34-0410-b5e6-96231b3b80d8