[interpreter] Update ForInPrepare to conditionally use runtime.

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_
 
 // Clients of this interface shouldn't depend on lots of interpreter internals.
 // Do not include anything from src/interpreter other than
 // src/interpreter/bytecodes.h here!
@@ skipping 125 matching lines @@
   compiler::Node* BuildLoadGlobal(Callable ic, InterpreterAssembler* assembler);
 
   // Generates code to load a named property.
   compiler::Node* BuildLoadNamedProperty(Callable ic,
                                          InterpreterAssembler* assembler);
 
   // Generates code to load a keyed property.
   compiler::Node* BuildLoadKeyedProperty(Callable ic,
                                          InterpreterAssembler* assembler);
 
+  // Generates code to prepare the result for ForInPrepare. Cache data
+  // are placed into the consecutive series of registers starting at
+  // |output_register|.
+  void BuildForInPrepareResult(compiler::Node* output_register,
+                               compiler::Node* cache_type,
+                               compiler::Node* cache_array,
+                               compiler::Node* cache_length,
+                               InterpreterAssembler* assembler);
+
   uintptr_t GetDispatchCounter(Bytecode from, Bytecode to) const;
 
   // Get dispatch table index of bytecode.
   static size_t GetDispatchTableIndex(Bytecode bytecode,
                                       OperandScale operand_scale);
 
   bool IsDispatchTableInitialized();
 
   static const int kNumberOfWideVariants = 3;
   static const int kDispatchTableSize = kNumberOfWideVariants * (kMaxUInt8 + 1);
   static const int kNumberOfBytecodes = static_cast<int>(Bytecode::kLast) + 1;
 
   Isolate* isolate_;
   Address dispatch_table_[kDispatchTableSize];
   v8::base::SmartArrayPointer<uintptr_t> bytecode_dispatch_counters_table_;
 
   DISALLOW_COPY_AND_ASSIGN(Interpreter);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_INTERPRETER_H_