[clang-tidy] Fix readability-braces-around-statements false positive

Summary:
This fixes a false-positive e.g. when string literals are returned from if statement.

This patch includes as well a small fix to includes and renames of the test suite that collided with the name of the check.

Reviewers: alexfh, hokein

Subscribers: hokein

Tags: #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D25558

llvm-svn: 284212