This is another check that I ported to clang-tidy from my colobot-lint tool.
As previously discussed on cfe-dev mailing list, this is one of those checks that I think is general and useful enough for contribution to clang-tidy.
This patch contains implementation of check taken from colobot-lint, but also extended a great deal, including FixIt hints for automated refactoring, exhaustive testcases, and user documentation.
We should move most of these matchers to ASTMatchers.h as they are very general.
For example, we already have isInteger() as a QualType matcher so adding isBool() makes sense.