[llvm] [IR] Add `llvm.sincos` intrinsic (PR #109825)

[Benjamin Maxwell via llvm-commits]

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@@ -4448,6 +4470,8 @@ void DAGTypeLegalizer::WidenVectorResult(SDNode *N, unsigned ResNo) {
     if (!TLI.isOperationLegalOrCustomOrPromote(N->getOpcode(), WideVecVT) &&
         TLI.isOperationExpand(N->getOpcode(), VT.getScalarType())) {
       Res = DAG.UnrollVectorOp(N, WideVecVT.getVectorNumElements());
+      if (N->getNumValues() == 2)
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MacDue wrote:

I'm not sure this should be implemented now. `DAG.UnrollVectorOp()` also asserts that the number of results is 1 or 2. I could just add an assert after the `if` that the number of results is 1 and leave further extension to when someone needs it? 

https://github.com/llvm/llvm-project/pull/109825