[clang] [CIR] Avoid folding non-integer constants as integer casts (PR #214551)

[Akimasa Watanuki via cfe-commits]

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@@ -975,6 +975,10 @@ OpFoldResult cir::CastOp::fold(FoldAdaptor adaptor) {
     return cir::PoisonAttr::get(getContext(), getType());
   }
 
+  // Propogate Undef value
----------------
Men-cotton wrote:

```suggestion
  // Propagate Undef value
```
Typo?

https://github.com/llvm/llvm-project/pull/214551