[turbofan] Add DebugBreak machine operator and support

src/code-stub-assembler.h

 // Copyright 2016 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_CODE_STUB_ASSEMBLER_H_
 #define V8_CODE_STUB_ASSEMBLER_H_
 
 #include "src/compiler/code-assembler.h"
 #include "src/objects.h"
 
@@ skipping 57 matching lines @@
   compiler::Node* SmiLessThanOrEqual(compiler::Node* a, compiler::Node* b);
   compiler::Node* SmiMin(compiler::Node* a, compiler::Node* b);
 
   // Allocate an object of the given size.
   compiler::Node* Allocate(compiler::Node* size, AllocationFlags flags = kNone);
   compiler::Node* Allocate(int size, AllocationFlags flags = kNone);
   compiler::Node* InnerAllocate(compiler::Node* previous, int offset);
   compiler::Node* InnerAllocate(compiler::Node* previous,
                                 compiler::Node* offset);
 
+  void Assert(compiler::Node* condition);
+
   // Check a value for smi-ness
   compiler::Node* WordIsSmi(compiler::Node* a);
   // Check that the value is a positive smi.
   compiler::Node* WordIsPositiveSmi(compiler::Node* a);
 
   void BranchIfSmiLessThan(compiler::Node* a, compiler::Node* b, Label* if_true,
                            Label* if_false) {
     BranchIf(SmiLessThan(a, b), if_true, if_false);
   }
 
@@ skipping 173 matching lines @@
                                        compiler::Node* top_adddress,
                                        compiler::Node* limit_address);
 
   static const int kElementLoopUnrollThreshold = 8;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CODE_STUB_ASSEMBLER_H_