Fix tests to be more specific.

The environments can inject some declaration in every translation unit,
which can match very generic matchers, thus failing the tests.

Summary:
Fix tests to be more specific.
The environments can inject some declaration in every translation unit,
which can match very generic matchers, thus failing the tests.

Reviewers: aaron.ballman

CC: klimek, cfe-commits, revane

Differential Revision: http://llvm-reviews.chandlerc.com/D1541

llvm-svn: 189587