[turbofan] Desugar lookup slot optimization in graph builder.

src/compiler/control-builders.h

 // 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.
 
 #ifndef V8_COMPILER_CONTROL_BUILDERS_H_
 #define V8_COMPILER_CONTROL_BUILDERS_H_
 
 #include "src/compiler/ast-graph-builder.h"
 #include "src/compiler/node.h"
 
@@ skipping 115 matching lines @@
 
   // Primitive control commands.
   void BeginBlock();
   void EndBlock();
 
   // Primitive support for break.
   void Break() final;
 
   // Compound control commands for conditional break.
   void BreakWhen(Node* condition, BranchHint = BranchHint::kNone);
+  void BreakUnless(Node* condition, BranchHint hint = BranchHint::kNone);
 
  private:
   Environment* break_environment_;  // Environment after the block exits.
 };
 
 
 // Tracks control flow for a try-catch statement.
 class TryCatchBuilder final : public ControlBuilder {
  public:
   explicit TryCatchBuilder(AstGraphBuilder* builder)
@@ skipping 43 matching lines @@
   Environment* finally_environment_;  // Environment for the 'finally' body.
   Node* token_node_;                  // Node for token in 'finally' body.
   Node* value_node_;                  // Node for value in 'finally' body.
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_CONTROL_BUILDERS_H_