[llvm] [InstCombine] Fold Minimum over Trailing/Leading Bits Counts (PR #90402)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

> > Could we use value tracking and support non-constant values and non-uniform vectors?
> 
> I don't think this transform is profitable for non-constant values.

But I'd still like this for non-uniform constant vectors

https://github.com/llvm/llvm-project/pull/90402