[interpreter] Update ForInPrepare to conditionally use runtime.

src/interpreter/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_INTERPRETER_INTERPRETER_ASSEMBLER_H_
 #define V8_INTERPRETER_INTERPRETER_ASSEMBLER_H_
 
 #include "src/allocation.h"
 #include "src/base/smart-pointers.h"
 #include "src/builtins/builtins.h"
@@ skipping 109 matching lines @@
                                 compiler::Node* first_arg,
                                 compiler::Node* arg_count);
 
   // Call runtime function with |arg_count| arguments and the first argument
   // located at |first_arg|.
   compiler::Node* CallRuntimeN(compiler::Node* function_id,
                                compiler::Node* context,
                                compiler::Node* first_arg,
                                compiler::Node* arg_count, int return_size = 1);
 
+  // Check the cache validity for |receiver|. Branch to |use_cache| if
+  // valid, otherwise branch to |use_runtime|.
+  void CheckEnumCache(compiler::Node* receiver,
+                      CodeStubAssembler::Label* use_cache,
+                      CodeStubAssembler::Label* use_runtime);
+
+  // Get the enumerable length from |map| and return the result as a Smi.
+  compiler::Node* EnumLength(compiler::Node* map);
+
   // Jump relative to the current bytecode by |jump_offset|.
   compiler::Node* Jump(compiler::Node* jump_offset);
 
   // Jump relative to the current bytecode by |jump_offset| if the
   // word values |lhs| and |rhs| are equal.
   void JumpIfWordEqual(compiler::Node* lhs, compiler::Node* rhs,
                        compiler::Node* jump_offset);
 
   // Jump relative to the current bytecode by |jump_offset| if the
   // word values |lhs| and |rhs| are not equal.
@@ skipping 120 matching lines @@
   compiler::Node* stack_pointer_before_call_;
 
   DISALLOW_COPY_AND_ASSIGN(InterpreterAssembler);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_INTERPRETER_ASSEMBLER_H_