[CodeGen] Fix warning in SelectionDAG getNode for EXTRACT_VECTOR_ELT

[dancgr]

Summary

Fix warning in SelectionDAG getNode for EXTRACT_VECTOR_ELT.

[efriedma]

I think this is obsolete due to D80208?

[dancgr]

@efriedma Thanks Eli, I will close it, as that other patch already fixed that issue.

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

assert(VT.getSizeInBits() >= N1.getValueType().getScalarSizeInBits() &&
            "The result of EXTRACT_VECTOR_ELT must be at least as wide as the \
              element type of the vector.");
 
     // Extract from an undefined value or using an undefined index is undefined.
     if (N1.isUndef() || N2.isUndef())
       return getUNDEF(VT);
 
     // EXTRACT_VECTOR_ELT of out-of-bounds element is an UNDEF
-    if (N2C && N2C->getAPIntValue().uge(N1.getValueType().getVectorNumElements()))
+    if (!N1.getValueType().isScalableVector() &&
+      N2C && N2C->getAPIntValue().uge(N1.getValueType().getVectorNumElements()))
       return getUNDEF(VT);
 
     // EXTRACT_VECTOR_ELT of CONCAT_VECTORS is often formed while lowering is
     // expanding copies of large vectors from registers.
     if (N2C &&
         N1.getOpcode() == ISD::CONCAT_VECTORS &&
         N1.getNumOperands() > 0) {
       unsigned Factor =