[llvm] [llvm][Tablegen][llvm-tblgen] Added keyword #undef to llvm-tblgen (PR #69135)

[Mehdi Amini via llvm-commits]

joker-eph wrote:

I kind of follow what you're saying, but it's not clear to me why this is a good structure or the problem it really solves (that is I see the "made up" structure you described, but haven't seen a strong need for this in the real world so far).
Having three different files for the conceptually three different thing to include should be fine here.

https://github.com/llvm/llvm-project/pull/69135