[llvm] [SDAG] Drop select -> fmax/min folding in SelectionDAGBuilder (PR #93575)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> @arsenm Have all (potential) regressions been fixed?

No. We at least should have the nnan cases to minimum/maximum combine handled 

https://github.com/llvm/llvm-project/pull/93575