Never filter-out compile errors in clang-tidy, display them as errors.

Summary:
No filters should affect the display of errors. Fixed a few tests,
which had compile errors.

We need to think what we should do with mapped errors (-Werror).

Reviewers: klimek

Reviewed By: klimek

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D3982