[Interpreter] Add support for Load / Store to Lookup slots.

src/compiler/interpreter-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_INTERPRETER_ASSEMBLER_H_
 #define V8_COMPILER_INTERPRETER_ASSEMBLER_H_
 
 // Clients of this interface shouldn't depend on lots of compiler internals.
 // Do not include anything from src/compiler here!
 #include "src/allocation.h"
@@ skipping 84 matching lines @@
 
   // Load |slot_index| from |context|.
   Node* LoadContextSlot(Node* context, int slot_index);
   Node* LoadContextSlot(Node* context, Node* slot_index);
   // Stores |value| into |slot_index| of |context|.
   Node* StoreContextSlot(Node* context, Node* slot_index, Node* value);
 
   // Load the TypeFeedbackVector for the current function.
   Node* LoadTypeFeedbackVector();
 
+  // Project the output value at index |index|
+  Node* Projection(int index, Node* node);
+
   // Call constructor |constructor| with |arg_count| arguments (not
   // including receiver) and the first argument located at
   // |first_arg|. The |new_target| is the same as the
   // |constructor| for the new keyword, but differs for the super
   // keyword.
   Node* CallConstruct(Node* new_target, Node* constructor, Node* first_arg,
                       Node* arg_count);
 
   // Call JSFunction or Callable |function| with |arg_count|
   // arguments (not including receiver) and the first argument
@@ skipping 83 matching lines @@
   bool code_generated_;
 
   DISALLOW_COPY_AND_ASSIGN(InterpreterAssembler);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INTERPRETER_ASSEMBLER_H_