[llvm] [LLVM] Specialize test suites for `TableGen` and `FileCheck` to use smaller set of dependencies (PR #155929)

[Chris B via llvm-commits]

llvm-beanz wrote:

@jurahul, restricting to top level directories makes sense. I worry that may still get unwieldy, but we can always try it and revisit.

https://github.com/llvm/llvm-project/pull/155929