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

[Julian Schmidt via cfe-commits]

https://github.com/5chmidti commented:

Generalizing this check to enforce either static or anonymous namespaces would be great, then it would not be specific to LLVM and projects using a similar style. So something like misc-static-or-anonymous-namespace.
WDYT?

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