[llvm] [IR] Add nowrap flags for trunc instruction (PR #85592)

[via llvm-commits]

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@@ -946,6 +946,56 @@ class PossiblyNonNegInst : public CastInst {
   }
 };
 
+/// Cast Instruction that can have a nowrap flags (only trunc)
+class PossiblyNoWrapInst : public CastInst {
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elhewaty wrote:

I will move it there, but shouldn't be `PossiblyNonNegInst` moved to `ZextInst` as well?

https://github.com/llvm/llvm-project/pull/85592