[clang-tools-extra] [clang-tidy] Add performance-redundant-lookup check (PR #125420)

[Balazs Benics via cfe-commits]

steakhal wrote:

> Performance looks good. Everything under 5% is acceptable.
> 
> The top three entries should probably get tickets so they get looked into. The amount seems too much for what it actually provides.

Yea, my idea was to give a bit of context of how it compares to the resr of the checks. Good to know its acceptable! Thanks.

https://github.com/llvm/llvm-project/pull/125420