Revert of [compiler] Drop the CompareNilIC.

src/compiler/change-lowering.cc

Index: src/compiler/change-lowering.cc
diff --git a/src/compiler/change-lowering.cc b/src/compiler/change-lowering.cc
index 907b36a93b7dd860c2a32e27a6b685444c9baf33..e217f3786b02c43ee5278b1c2555108857d24832 100644
--- a/src/compiler/change-lowering.cc
+++ b/src/compiler/change-lowering.cc
@@ -55,8 +55,6 @@
       return ObjectIsSmi(node);
     case IrOpcode::kObjectIsNumber:
       return ObjectIsNumber(node);
-    case IrOpcode::kObjectIsUndetectable:
-      return ObjectIsUndetectable(node);
     default:
       return NoChange();
   }
@@ -605,13 +603,6 @@
       graph()->start(), control);
 }
 
-Node* ChangeLowering::LoadMapBitField(Node* map) {
-  return graph()->NewNode(
-      machine()->Load(MachineType::Uint8()), map,
-      jsgraph()->IntPtrConstant(Map::kBitFieldOffset - kHeapObjectTag),
-      graph()->start(), graph()->start());
-}
-
 Node* ChangeLowering::LoadMapInstanceType(Node* map) {
   return graph()->NewNode(
       machine()->Load(MachineType::Uint8()), map,
@@ -659,31 +650,6 @@
   return Changed(node);
 }
 
-Reduction ChangeLowering::ObjectIsUndetectable(Node* node) {
-  Node* input = NodeProperties::GetValueInput(node, 0);
-  // TODO(bmeurer): Optimize somewhat based on input type.
-  Node* check = IsSmi(input);
-  Node* branch = graph()->NewNode(common()->Branch(), check, graph()->start());
-  Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
-  Node* vtrue = jsgraph()->Int32Constant(0);
-  Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
-  Node* vfalse = graph()->NewNode(
-      machine()->Word32Equal(),
-      graph()->NewNode(
-          machine()->Word32Equal(),
-          graph()->NewNode(machine()->Word32And(),
-                           jsgraph()->Uint32Constant(1 << Map::kIsUndetectable),
-                           LoadMapBitField(LoadHeapObjectMap(input, if_false))),
-          jsgraph()->Int32Constant(0)),
-      jsgraph()->Int32Constant(0));
-  Node* control = graph()->NewNode(common()->Merge(2), if_true, if_false);
-  node->ReplaceInput(0, vtrue);
-  node->AppendInput(graph()->zone(), vfalse);
-  node->AppendInput(graph()->zone(), control);
-  NodeProperties::ChangeOp(node, common()->Phi(MachineRepresentation::kBit, 2));
-  return Changed(node);
-}
-
 Reduction ChangeLowering::ObjectIsSmi(Node* node) {
   node->ReplaceInput(0,
                      graph()->NewNode(machine()->WordAnd(), node->InputAt(0),