[interpreter] Add a fast path for dynamic local load

src/interpreter/interpreter.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_INTERPRETER_INTERPRETER_H_
 #define V8_INTERPRETER_INTERPRETER_H_
 
 #include <memory>
 
 // Clients of this interface shouldn't depend on lots of interpreter internals.
@@ skipping 114 matching lines @@
   void DoJSCall(InterpreterAssembler* assembler, TailCallMode tail_call_mode);
 
   // Generates code to perform delete via function_id.
   void DoDelete(Runtime::FunctionId function_id,
                 InterpreterAssembler* assembler);
 
   // Generates code to perform a lookup slot load via |function_id|.
   void DoLdaLookupSlot(Runtime::FunctionId function_id,
                        InterpreterAssembler* assembler);
 
+  // Generates code to perform a lookup slot load via |function_id| that can
+  // fast path to a context slot load
+  void DoLdaLookupContextSlot(Runtime::FunctionId function_id,
+                              InterpreterAssembler* assembler);
+
   // Generates code to perform a lookup slot store depending on |language_mode|.
   void DoStaLookupSlot(LanguageMode language_mode,
                        InterpreterAssembler* assembler);
 
   // Generates code to load a context slot.
   compiler::Node* BuildLoadContextSlot(InterpreterAssembler* assembler);
 
   // Generates code to load a global.
   compiler::Node* BuildLoadGlobal(Callable ic, InterpreterAssembler* assembler);
 
@@ skipping 35 matching lines @@
   std::unique_ptr<uintptr_t[]> bytecode_dispatch_counters_table_;
 
   DISALLOW_COPY_AND_ASSIGN(Interpreter);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_INTERPRETER_H_