[clang-tools-extra] [clang-tidy] Add new check `llvm-prefer-static-over-anonymous-namespace` (PR #142839)

[Baranov Victor via cfe-commits]

vbvictor wrote:

@AaronBallman, may you give some feedback on how good/bad this check would play on LLVM project in general.
I feel it may be even "too strict" for whole LLVM, but for clang-tidy project it may be very helpful in guiding new contributors writing the right way.


https://github.com/llvm/llvm-project/pull/142839