[clang-tools-extra] [clang-tidy] Add check for assignment or comparision operators' operand in `readability-math-missing-parentheses` (PR #141345)

[via cfe-commits]

flovent wrote:

Thanks for catching, CHECK-FIXES added.

> I don't know why tests didn't fail because of it, needs some investigation.

I don't know either, but the check does produce `FixIt`, and it seems `CHECK-FIXES` is optional in this test file, doesn't affect whether the test pass.

https://github.com/llvm/llvm-project/pull/141345