[llvm] [RISCV] Make xrivosvizip interleave2 and deinterleave2 undef safe (PR #136733)

[Luke Lau via llvm-commits]

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@@ -11543,6 +11543,8 @@ SDValue RISCVTargetLowering::lowerVECTOR_DEINTERLEAVE(SDValue Op,
       EVT NewVT = VT.getDoubleNumVectorElementsVT();
       SDValue ZeroIdx = DAG.getVectorIdxConstant(0, DL);
       Src = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, NewVT, Src, ZeroIdx);
+      // Freeze the source so we can increase it's use count.
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lukel97 wrote:

Nit
```suggestion
      // Freeze the source so we can increase its use count.
```

https://github.com/llvm/llvm-project/pull/136733