[Interpreter] Add support for for..in.

src/interpreter/control-flow-builders.cc

 // 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.
 
 #include "src/interpreter/control-flow-builders.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
@@ skipping 13 matching lines @@
   BindLabels(target, &break_sites_);
 }
 
 
 void LoopBuilder::EmitJump(ZoneVector<BytecodeLabel>* sites) {
   sites->push_back(BytecodeLabel());
   builder()->Jump(&sites->back());
 }
 
 
+void LoopBuilder::EmitJumpIfTrue(ZoneVector<BytecodeLabel>* sites) {
+  sites->push_back(BytecodeLabel());
+  builder()->JumpIfTrue(&sites->back());
+}
+
+
+void LoopBuilder::EmitJumpIfUndefined(ZoneVector<BytecodeLabel>* sites) {
+  sites->push_back(BytecodeLabel());
+  builder()->JumpIfUndefined(&sites->back());
+}
+
+
+void LoopBuilder::EmitJumpIfNull(ZoneVector<BytecodeLabel>* sites) {
+  sites->push_back(BytecodeLabel());
+  builder()->JumpIfNull(&sites->back());
+}
+
+
 void LoopBuilder::BindLabels(const BytecodeLabel& target,
                              ZoneVector<BytecodeLabel>* sites) {
   for (size_t i = 0; i < sites->size(); i++) {
     BytecodeLabel& site = sites->at(i);
     builder()->Bind(target, &site);
   }
   sites->clear();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8