First simple implementation of for-of in TurboFan.

src/compiler/control-builders.cc

Index: src/compiler/control-builders.cc
diff --git a/src/compiler/control-builders.cc b/src/compiler/control-builders.cc
index 2978d8b6484a0fd2f0709b971db14cb3e9b2fc52..6cf2905e613e3e6b4837a262cbe1c3588906d606 100644
--- a/src/compiler/control-builders.cc
+++ b/src/compiler/control-builders.cc
@@ -73,6 +73,16 @@ void LoopBuilder::BreakUnless(Node* condition) {
 }
 
 
+void LoopBuilder::BreakWhen(Node* condition) {
+  IfBuilder control_if(builder_);
+  control_if.If(condition);
+  control_if.Then();
+  Break();
+  control_if.Else();
+  control_if.End();
+}
+
+
 void SwitchBuilder::BeginSwitch() {
   body_environment_ = environment()->CopyAsUnreachable();
   label_environment_ = environment()->CopyAsUnreachable();