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

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 {
+
+
+LoopBuilder::~LoopBuilder() {
+  BindLabels(continue_label(), &continue_labels_);
+  BindLabels(break_label(), &break_labels_);

[rmcilroy, 2015/10/01 09:18:56]

Either move this to an explicit function or call this LoopBuilderScope to make
it clear that it is scoped.

[oth, 2015/10/01 11:43:02]

Done.

+}
+
+
+void LoopBuilder::Break() {
+  break_labels_.push_back(BytecodeLabel());
+  builder()->Jump(&break_labels_.back());
+}
+
+
+void LoopBuilder::Continue() {
+  continue_labels_.push_back(BytecodeLabel());
+  builder()->Jump(&continue_labels_.back());
+}
+
+
+void LoopBuilder::BindLabels(BytecodeLabel* target,
+                             ZoneVector<BytecodeLabel>* labels) {
+  for (size_t i = 0; i < labels->size(); i++) {
+    BytecodeLabel& unbound = labels->at(i);
+    builder()->Bind(&unbound, target);
+  }
+}
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8