[turbofan] Finish support for holey double elements backing stores.

src/compiler/simplified-lowering.cc

Index: src/compiler/simplified-lowering.cc
diff --git a/src/compiler/simplified-lowering.cc b/src/compiler/simplified-lowering.cc
index 92a6bb5283d040a70c36ba7de794eb3e73efd9de..6dfc9ae9fc57693aaa02792c32d4fe99638f32c2 100644
--- a/src/compiler/simplified-lowering.cc
+++ b/src/compiler/simplified-lowering.cc
@@ -776,6 +776,21 @@ class RepresentationSelector {
         }
         break;
       }
+      case IrOpcode::kNumberIsHoleNaN: {
+        VisitUnop(node, kMachFloat64, kMachBool);
+        if (lower()) {
+          // NumberIsHoleNaN(x) => Word32Equal(Float64ExtractLowWord32(x),
+          //                                   #HoleNaNLower32)
+          node->ReplaceInput(0,
+                             jsgraph_->graph()->NewNode(
+                                 lowering->machine()->Float64ExtractLowWord32(),
+                                 node->InputAt(0)));
+          node->AppendInput(jsgraph_->zone(),
+                            jsgraph_->Int32Constant(kHoleNanLower32));
+          NodeProperties::ChangeOp(node, jsgraph_->machine()->Word32Equal());
+        }
+        break;
+      }
       case IrOpcode::kPlainPrimitiveToNumber: {
         VisitUnop(node, kMachAnyTagged, kTypeNumber | kRepTagged);
         if (lower()) {