[clang-tools-extra] [clang-tidy] Prefer the faster LLVM ADT sets and maps over `std::` ones (PR #174357)

[Carlos Galvez via cfe-commits]

carlosgalvezp wrote:

Personally I think this is a micro-optimization that makes the code less readable (have to know which ADT type to use, have to switch to .begin()/.end(), etc) and increases the possibilities of bugs (e.g Impl vs non-Impl classes).

People will continue to use the STL containers anyway, since that's the most natural choice and there's no enforcement. There's also history of replacing ADT types with STL ones (e.g. std::optional). 

So I would be softly opposed to this change, but if other people believe it's worth it I'm ok with merging.

https://github.com/llvm/llvm-project/pull/174357