[llvm] [RISCV] Add codegen support for ri.vinsert.v.x and ri.vextract.x.v (PR #136708)

[Luke Lau via llvm-commits]

================
@@ -9576,6 +9576,13 @@ getSmallestVTForIndex(MVT VecVT, unsigned MaxIdx, SDLoc DL, SelectionDAG &DAG,
   return SmallerVT;
 }
 
+static bool isValidInsertExtractIndex(SDValue Idx) {
+  auto *IdxC = dyn_cast<ConstantSDNode>(Idx);
+  if (!IdxC || isNullConstant(Idx))
+    return false;
+  return IdxC->getZExtValue() < 32;
----------------
lukel97 wrote:

Nit
```suggestion
  return isUInt<5>(IdxC->getZExtValue());
```

https://github.com/llvm/llvm-project/pull/136708