Debugger: use debug break slots instead of ICs (except for calls).

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1067 matching lines @@
     return state_.current_statement_position;
   }
 
  private:
   Assembler* assembler_;
   PositionState state_;
 
   // Currently jit_handler_data_ is used to store JITHandler-specific data
   // over the lifetime of a PositionsRecorder
   void* jit_handler_data_;
-  friend class PreservePositionScope;
 
   DISALLOW_COPY_AND_ASSIGN(PositionsRecorder);
 };
 
 
-class PreservePositionScope BASE_EMBEDDED {
- public:
-  explicit PreservePositionScope(PositionsRecorder* positions_recorder)
-      : positions_recorder_(positions_recorder),
-        saved_state_(positions_recorder->state_) {
-    // Reset positions so that previous ones do not accidentally get
-    // recorded within this scope.
-    positions_recorder->state_ = PositionState();
-  }
-
-  ~PreservePositionScope() {
-    positions_recorder_->state_ = saved_state_;
-  }
-
- private:
-  PositionsRecorder* positions_recorder_;
-  const PositionState saved_state_;
-
-  DISALLOW_COPY_AND_ASSIGN(PreservePositionScope);
-};
-
-
 // -----------------------------------------------------------------------------
 // Utility functions
 
 inline int NumberOfBitsSet(uint32_t x) {
   unsigned int num_bits_set;
   for (num_bits_set = 0; x; x >>= 1) {
     num_bits_set += x & 1;
   }
   return num_bits_set;
 }
@@ skipping 144 matching lines @@
   };
 
   Label emitted_label_;  // Records pc_offset of emitted pool
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_