[llvm-branch-commits] [ConstantFolding] Avoid use of isNonIntegralPointerType() (PR #159959)

[Alexander Richardson via llvm-branch-commits]

https://github.com/arichardson created https://github.com/llvm/llvm-project/pull/159959

Avoiding any new inttoptr is unnecessarily restrictive for "plain"
non-integral pointers, but it is important for unstable pointers and
pointers with external state. Fixes another test codegen regression
from https://github.com/llvm/llvm-project/pull/105735.