[turbofan] First step towards sanitizing for-in and making it optimizable.

src/compiler/control-builders.cc

 // Copyright 2013 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 "control-builders.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
@@ skipping 125 matching lines @@
   break_environment_ = environment()->CopyAsUnreachable();
 }
 
 
 void BlockBuilder::Break() {
   break_environment_->Merge(environment());
   environment()->MarkAsUnreachable();
 }
 
 
+void BlockBuilder::BreakWhen(Node* condition, BranchHint hint) {
+  IfBuilder control_if(builder_);
+  control_if.If(condition, hint);
+  control_if.Then();
+  Break();
+  control_if.Else();
+  control_if.End();
+}
+
+
 void BlockBuilder::EndBlock() {
   break_environment_->Merge(environment());
   set_environment(break_environment_);
 }
 
 
 void TryCatchBuilder::BeginTry() {
   catch_environment_ = environment()->CopyAsUnreachable();
   catch_environment_->Push(the_hole());
 }
@@ skipping 46 matching lines @@
 }
 
 
 void TryFinallyBuilder::EndFinally() {
   // Nothing to be done here.
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8