[clang-tidy] Lift parsing of sequence of names functions to utils.

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
6 files changed