[Interpreter] Pass context to interpreter bytecode handlers and add LoadConstextSlot

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 35 matching lines @@
   // Accumulator.
   Node* GetAccumulator();
   void SetAccumulator(Node* value);
 
   // Loads from and stores to the interpreter register file.
   Node* LoadRegister(Node* reg_index);
   Node* StoreRegister(Node* value, Node* reg_index);
 
   // Constants.
   Node* Int32Constant(int value);
+  Node* IntPtrConstant(intptr_t value);
   Node* NumberConstant(double value);
   Node* HeapConstant(Unique<HeapObject> object);
 
   // Tag and untag Smi values.
   Node* SmiTag(Node* value);
   Node* SmiUntag(Node* value);
 
+  // Load |slot_index| from the current context.
+  Node* LoadContextSlot(int slot_index);
+
   // Returns from the function.
   void Return();
 
   // Dispatch to the bytecode.
   void Dispatch();
 
  protected:
   // Close the graph.
   void End();
 
   // Protected helpers (for testing) which delegate to RawMachineAssembler.
   CallDescriptor* call_descriptor() const;
   Graph* graph();
 
  private:
   // Returns a raw pointer to start of the register file on the stack.
   Node* RegisterFileRawPointer();
   // Returns a tagged pointer to the current function's BytecodeArray object.
   Node* BytecodeArrayTaggedPointer();
   // Returns the offset from the BytecodeArrayPointer of the current bytecode.
   Node* BytecodeOffset();
-  // Returns a pointer to first entry in the interpreter dispatch table.
+  // Returns a raw pointer to first entry in the interpreter dispatch table.
   Node* DispatchTableRawPointer();
+  // Returns a tagged pointer to the current context.
+  Node* ContextTaggedPointer();
 
   // Returns the offset of register |index| relative to RegisterFilePointer().
   Node* RegisterFrameOffset(Node* index);
 
   Node* SmiShiftBitsConstant();
   Node* BytecodeOperand(int operand_index);
   Node* BytecodeOperandSignExtended(int operand_index);
 
   // Returns BytecodeOffset() advanced by delta bytecodes. Note: this does not
   // update BytecodeOffset() itself.
@@ skipping 13 matching lines @@
   bool code_generated_;
 
   DISALLOW_COPY_AND_ASSIGN(InterpreterAssembler);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_INTERPRETER_ASSEMBLER_H_