Revert of [compiler] Drop the CompareNilIC.

src/compiler/change-lowering.h

Index: src/compiler/change-lowering.h
diff --git a/src/compiler/change-lowering.h b/src/compiler/change-lowering.h
index 7e5078bf84bed20e0fe8f7fa12bbc9a6821e0876..defadd95fd098d65f4ce9cd201158e34c67afe52 100644
--- a/src/compiler/change-lowering.h
+++ b/src/compiler/change-lowering.h
@@ -58,13 +58,11 @@
 
   Node* IsSmi(Node* value);
   Node* LoadHeapObjectMap(Node* object, Node* control);
-  Node* LoadMapBitField(Node* map);
   Node* LoadMapInstanceType(Node* map);
 
   Reduction ObjectIsNumber(Node* node);
   Reduction ObjectIsReceiver(Node* node);
   Reduction ObjectIsSmi(Node* node);
-  Reduction ObjectIsUndetectable(Node* node);
 
   Node* ComputeIndex(const ElementAccess& access, Node* const key);
   Graph* graph() const;