[llvm] [InstCombine] Remove some of the complexity-based canonicalization (PR #91185)

[via llvm-commits]

goldsteinn wrote:

> > Can you run it? Ill try and get -stats to work locally and post them here.
> 
> I cannot run it as LLVM doesn't support the cost estimation of struct types :(

Err misunderstanding, I mean can you just generate your normal diffs. Ill do the cost estimation stuff locally and just post the results here.

https://github.com/llvm/llvm-project/pull/91185