[clang-tools-extra] [clang-tidy][NFC] Enable 'readability-simplify-boolean-expr' check (PR #158706)

[Davide Cunial via cfe-commits]

capitan-davide wrote:

> I enabled `IgnoreMacros` when running this check over my work code base, since a lot of warnings were related to stuff like asserts.

Even though there are a number of `assert`s in clang-tools-extra/clang-tidy, looks like this check never fired in this codebase :thinking: .. are there certain pattern that could be problematic?

https://github.com/llvm/llvm-project/pull/158706