[llvm] [mlir] [mlir] split transform interfaces into a separate library (PR #85221)

[Mehdi Amini via llvm-commits]

joker-eph wrote:

> IMO, transform interfaces belong to lib/Interface, and I wanted that from the early days. 

Right, to me this was only a question of maturity. Something like the transform dialect is just are core infra as the patterns mechanism, PDL, etc.

This should be a hard dependency on the core IR (in MLIR you always pay only for what you use), but it's part of these off-the-shelves convenient components that gets well integrated in the core infra.

https://github.com/llvm/llvm-project/pull/85221