[llvm] [LLVM][AArch64] Enable verifyTargetSDNode for scalable vectors and fix the fallout. (PR #104820)

[Matthew Devereau via llvm-commits]

================
@@ -29363,12 +29389,25 @@ void AArch64TargetLowering::verifyTargetSDNode(const SDNode *N) const {
     EVT Op1VT = N->getOperand(1).getValueType();
     assert(VT.isVector() && Op0VT.isVector() && Op1VT.isVector() &&
            "Expected vectors!");
-    // TODO: Enable assert once bogus creations have been fixed.
-    if (VT.isScalableVector())
-      break;
     assert(VT == Op0VT && VT == Op1VT && "Expected matching vectors!");
     break;
   }
+  case AArch64ISD::RSHRNB_I: {
+    assert(N->getNumValues() == 1 && "Expected one result!");
+    assert(N->getNumOperands() == 2 && "Expected two operand!");
----------------
MDevereau wrote:

```suggestion
    assert(N->getNumOperands() == 2 && "Expected two operands!");
```

https://github.com/llvm/llvm-project/pull/104820