Thread Safety Analysis: now with less includes. No functional changes.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@205929 91177308-0d34-0410-b5e6-96231b3b80d8
Switching back from a static namespace-scoped function to a static class-scope function. No functional change, but resolves a warning.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@205931 91177308-0d34-0410-b5e6-96231b3b80d8