[Interpreter] Add support for for..in.

src/interpreter/bytecode-array-builder.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_BYTECODE_ARRAY_BUILDER_H_
 #define V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_
 
 #include <vector>
 
 #include "src/ast.h"
@@ skipping 167 matching lines @@
   BytecodeArrayBuilder& JumpIfFalse(BytecodeLabel* label);
   // TODO(mythria) The following two functions should be merged into
   // JumpIfTrue/False. These bytecodes should be automatically chosen rather
   // than explicitly using them.
   BytecodeArrayBuilder& JumpIfToBooleanTrue(BytecodeLabel* label);
   BytecodeArrayBuilder& JumpIfToBooleanFalse(BytecodeLabel* label);
 
   BytecodeArrayBuilder& Throw();
   BytecodeArrayBuilder& Return();
 
+  // Complex flow control.
+  BytecodeArrayBuilder& ForInPrepare();
+  BytecodeArrayBuilder& ForInNext(Register for_in_state);
+  BytecodeArrayBuilder& ForInDone(Register for_in_state);
+
   BytecodeArrayBuilder& EnterBlock();
   BytecodeArrayBuilder& LeaveBlock();
 
   // Accessors
   Zone* zone() const { return zone_; }
 
  private:
   ZoneVector<uint8_t>* bytecodes() { return &bytecodes_; }
   const ZoneVector<uint8_t>* bytecodes() const { return &bytecodes_; }
   Isolate* isolate() const { return isolate_; }
@@ skipping 77 matching lines @@
 
  private:
   static const size_t kInvalidOffset = static_cast<size_t>(-1);
 
   INLINE(void bind_to(size_t offset)) {
     DCHECK(!bound_ && offset != kInvalidOffset);
     offset_ = offset;
     bound_ = true;
   }
   INLINE(void set_referrer(size_t offset)) {
-    DCHECK(!bound_ && offset != kInvalidOffset);
+    DCHECK(!bound_ && offset != kInvalidOffset && offset_ == kInvalidOffset);
     offset_ = offset;
   }
   INLINE(size_t offset() const) { return offset_; }
   INLINE(bool is_bound() const) { return bound_; }
   INLINE(bool is_forward_target() const) {
     return offset() != kInvalidOffset && !is_bound();
   }
 
   // There are three states for a label:
   //                    bound_   offset_
@@ skipping 32 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(TemporaryRegisterScope);
 };
 
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_ARRAY_BUILDER_H_