[Interpreter] Add for/while/do support to the bytecode generator.

src/interpreter/control-flow-builders.cc

Index: src/interpreter/control-flow-builders.cc
diff --git a/src/interpreter/control-flow-builders.cc b/src/interpreter/control-flow-builders.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6c634bbe841d277566cf29884f35c7ab078d878d
--- /dev/null
+++ b/src/interpreter/control-flow-builders.cc
@@ -0,0 +1,45 @@
+// 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 {
+
+
+LoopBuilder::~LoopBuilder() {
+  DCHECK(continue_sites_.empty());
+  DCHECK(break_sites_.empty());
+}
+
+
+void LoopBuilder::SetContinueTarget(const BytecodeLabel& target) {
+  BindLabels(target, &continue_sites_);
+}
+
+
+void LoopBuilder::SetBreakTarget(const BytecodeLabel& target) {
+  BindLabels(target, &break_sites_);
+}
+
+
+void LoopBuilder::EmitJump(ZoneVector<BytecodeLabel>* sites) {
+  sites->push_back(BytecodeLabel());
+  builder()->Jump(&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