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

[Min-Yih Hsu via llvm-commits]

mshockwave wrote:

> I understand the utility of what you're trying to do here, but I worry that if we extrapolate this pattern out across the test subdirectories we're going to create an unmanageable mess.
> 
> Every subdirectory under the test suite gets its own target, and if each target gets configured for its own dependency subset manually we're creating a real mess to maintain.

For codegen and the middle-end tests like Analysis and Transforms, this (relatively short) list of dependencies doesn't change really frequently, so personally I'm not super worry about managing lists in those places. That being said, some places like MC might have a more diversified dependencies.
I think a tradeoff we can make here is to limit the granularity, for instance limiting to top-level directories immediate under `test`.

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