[llvm] [IRBuilder][GlobalISel] Add byte ptr cast support in IRBuilder (PR #222049)

[Jameson Nash via llvm-commits]

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@@ -140,9 +146,7 @@ Value *IRBuilderBase::CreateBitPreservingCastChain(const DataLayout &DL,
   };
 
   // See if we need inttoptr for this type pair. May require additional bitcast.
-  bool OldIsIntLike =
-      OldTy->isIntOrIntVectorTy() || OldTy->isByteOrByteVectorTy();
-  if (OldIsIntLike && NewTy->isPtrOrPtrVectorTy()) {
+  if (OldTy->isIntOrIntVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
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vtjnash wrote:

I think the more correct check here is that inttoptr is needed whenever it is changing from not a pointer to a pointer (easier than trying to hardcodw a list of all non-pointer things):

```suggestion
  if (!OldTy->isPtrOrPtrVectorTy() && NewTy->isPtrOrPtrVectorTy()) {
```

(And the same below. Following https://github.com/llvm/llvm-project/pull/186835/changes#diff-7b9ae5c1774880299e98d0bd713f6d0b881a6f70ad31ce5603ea6275fecf8a42R142)

https://github.com/llvm/llvm-project/pull/222049