[clang] Skip over std namespace in WebKit checkers. (PR #90552)

[Ryosuke Niwa via cfe-commits]

rniwa wrote:

> Ok am I reading this right: this is about testing code that lives directly in namespace `std::` but somehow still lives in your project right? Such as your custom modifications to standard classes, various overloads and specializations of standard things.

No, this is about standard library code getting warnings.

> This patch does not affect the behavior of checkers when you're just passing raw pointers from user code to standard functions such as `std::memcpy()`. You still want to have a warning about those.

Right. But we don't want code within standard library to give warnings.

> And generally you already don't have any warnings about things that's going on in system headers themselves. There's a separate suppression about that.

Hm... it's odd that we're getting warnings there then.

https://github.com/llvm/llvm-project/pull/90552