[turbofan] Remove self-healing wrt. ChangeFloat64ToTagged.

Make sure that the input to ChangeFloat64ToTagged is definitely of type
Number, because the operator cannot deal with non-Number inputs.

R=jarin@chromium.org
BUG=v8:5267

Review-Url: https://codereview.chromium.org/2858153003
Cr-Commit-Position: refs/heads/master@{#45087}

src/compiler/representation-change.cc

@@ -364,12 +364,22 @@ Node* RepresentationChanger::GetTaggedPointerRepresentationFor(
     }
     op = simplified()->ChangeFloat64ToTaggedPointer();
   } else if (output_rep == MachineRepresentation::kFloat32) {
-    // float32 -> float64 -> tagged
-    node = InsertChangeFloat32ToFloat64(node);
-    op = simplified()->ChangeFloat64ToTaggedPointer();
+    if (output_type->Is(Type::Number())) {
+      // float32 -> float64 -> tagged
+      node = InsertChangeFloat32ToFloat64(node);
+      op = simplified()->ChangeFloat64ToTaggedPointer();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kTaggedPointer);
+    }
   } else if (output_rep == MachineRepresentation::kFloat64) {
-    // float64 -> tagged
-    op = simplified()->ChangeFloat64ToTaggedPointer();
+    if (output_type->Is(Type::Number())) {
+      // float64 -> tagged
+      op = simplified()->ChangeFloat64ToTaggedPointer();
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kTaggedPointer);
+    }
   } else if (CanBeTaggedSigned(output_rep) &&
              use_info.type_check() == TypeCheckKind::kHeapObject) {
     if (!output_type->Maybe(Type::SignedSmall())) {
@@ -452,11 +462,14 @@ Node* RepresentationChanger::GetTaggedRepresentationFor(
                    Type::Unsigned32())) {  // float64 -> uint32 -> tagged
       node = InsertChangeFloat64ToUint32(node);
       op = simplified()->ChangeUint32ToTagged();
-    } else {
+    } else if (output_type->Is(Type::Number())) {
       op = simplified()->ChangeFloat64ToTagged(
           output_type->Maybe(Type::MinusZero())
               ? CheckForMinusZeroMode::kCheckForMinusZero
               : CheckForMinusZeroMode::kDontCheckForMinusZero);
+    } else {
+      return TypeError(node, output_rep, output_type,
+                       MachineRepresentation::kTagged);
     }
   } else {
     return TypeError(node, output_rep, output_type,