[llvm] [IR] Add support for `nneg` flag with `uitofp` (PR #86141)

[Nikita Popov via llvm-commits]

================
@@ -2143,12 +2137,15 @@ class IRBuilderBase {
   }
 
   Value *CreateCast(Instruction::CastOps Op, Value *V, Type *DestTy,
-                    const Twine &Name = "") {
+                    const Twine &Name = "", bool IsNonNeg = false) {
----------------
nikic wrote:

I think I'd rather not have this, given how the flag does not apply to all casts.

https://github.com/llvm/llvm-project/pull/86141