[turbofan] Add DebugBreak machine operator and support

src/compiler/raw-machine-assembler.h

 // Copyright 2014 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_RAW_MACHINE_ASSEMBLER_H_
 #define V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_
 
 #include "src/assembler.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
@@ skipping 679 matching lines @@
   void Goto(RawMachineLabel* label);
   void Branch(Node* condition, RawMachineLabel* true_val,
               RawMachineLabel* false_val);
   void Switch(Node* index, RawMachineLabel* default_label, int32_t* case_values,
               RawMachineLabel** case_labels, size_t case_count);
   void Return(Node* value);
   void Return(Node* v1, Node* v2);
   void Return(Node* v1, Node* v2, Node* v3);
   void Bind(RawMachineLabel* label);
   void Deoptimize(Node* state);
+  void DebugBreak();
 
   // Variables.
   Node* Phi(MachineRepresentation rep, Node* n1, Node* n2) {
     return AddNode(common()->Phi(rep, 2), n1, n2, graph()->start());
   }
   Node* Phi(MachineRepresentation rep, Node* n1, Node* n2, Node* n3) {
     return AddNode(common()->Phi(rep, 3), n1, n2, n3, graph()->start());
   }
   Node* Phi(MachineRepresentation rep, Node* n1, Node* n2, Node* n3, Node* n4) {
     return AddNode(common()->Phi(rep, 4), n1, n2, n3, n4, graph()->start());
@@ skipping 58 matching lines @@
   bool deferred_;
   friend class RawMachineAssembler;
   DISALLOW_COPY_AND_ASSIGN(RawMachineLabel);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_RAW_MACHINE_ASSEMBLER_H_