[llvm] [IR] Remove zext and sext constant expressions (PR #71040)

[Nicolai Hähnle via llvm-commits]

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@@ -1461,17 +1411,13 @@ static ICmpInst::Predicate evaluateICmpRelation(Constant *V1, Constant *V2,
       [[fallthrough]];
     case Instruction::UIToFP:
     case Instruction::SIToFP:
-    case Instruction::ZExt:
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nhaehnle wrote:

This code puzzles me. Not so much your change to it, but...

The method is called `evaluateICmpRelation`, and a whole lot of comments talk about how we can't evaluate floating point values. So how can we ever get the `UIToFP` or `SIToFP` cases here?

https://github.com/llvm/llvm-project/pull/71040