[llvm] [VPlan] Support struct return types for widen intrinsics (NFC). (PR #165218)

[Benjamin Maxwell via llvm-commits]

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@@ -164,6 +164,11 @@ LLVM_ABI bool
 isVectorIntrinsicWithOverloadTypeAtArg(Intrinsic::ID ID, int OpdIdx,
                                        const TargetTransformInfo *TTI);
 
+/// Identifies if the vector form of the intrinsic that returns a struct has
+/// a scalar element at the struct element index \p RetIdx.
+LLVM_ABI bool isVectorIntrinsicWithStructReturnScalarAtField(Intrinsic::ID ID,
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MacDue wrote:

You may need to move this to `llvm/include/llvm/IR/VectorTypeUtils.h` (same for the impl) to avoid linker issues. 

https://github.com/llvm/llvm-project/pull/165218