[llvm] [LLVM][ConstantFold] Ensure scalar type is queried when determining denormal mode. (PR #189600)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm approved this pull request.

I still do not believe any of this constant folding code should be inspecting the denormal mode, and just unconditionally not flush 

https://github.com/llvm/llvm-project/pull/189600