Revert of Migrate FastCloneShallowObjectStub to TurboFan

src/compiler/code-stub-assembler.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_CODE_STUB_ASSEMBLER_H_
 #define V8_COMPILER_CODE_STUB_ASSEMBLER_H_
 
 #include <map>
 
 // Clients of this interface shouldn't depend on lots of compiler internals.
@@ skipping 322 matching lines @@
   Node* LoadMapBitField2(Node* map);
   // Load bit field 3 of a map.
   Node* LoadMapBitField3(Node* map);
   // Load the instance type of a map.
   Node* LoadMapInstanceType(Node* map);
   // Load the instance descriptors of a map.
   Node* LoadMapDescriptors(Node* map);
 
   // Load the hash field of a name.
   Node* LoadNameHash(Node* name);
-  // Load the instance size of a Map.
-  Node* LoadMapInstanceSize(Node* map);
 
   // Load an array element from a FixedArray.
   Node* LoadFixedArrayElementInt32Index(Node* object, Node* int32_index,
                                         int additional_offset = 0);
   Node* LoadFixedArrayElementSmiIndex(Node* object, Node* smi_index,
                                       int additional_offset = 0);
   Node* LoadFixedArrayElementConstantIndex(Node* object, int index);
 
   // Allocate an object of the given size.
   Node* Allocate(int size, AllocationFlags flags = kNone);
@@ skipping 152 matching lines @@
   // Map of variables to the list of value nodes that have been added from each
   // merge path in their order of merging.
   std::map<Variable::Impl*, std::vector<Node*>> variable_merges_;
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CODE_STUB_ASSEMBLER_H_