[debug] always add debug slot for statements.

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 1134 matching lines @@
 class AssemblerPositionsRecorder : public PositionsRecorder {
  public:
   explicit AssemblerPositionsRecorder(Assembler* assembler)
       : assembler_(assembler),
         current_position_(RelocInfo::kNoPosition),
         written_position_(RelocInfo::kNoPosition),
         current_statement_position_(RelocInfo::kNoPosition),
         written_statement_position_(RelocInfo::kNoPosition) {}
 
   // Set current position to pos.
-  bool RecordPosition(int pos);
+  void RecordPosition(int pos);
 
   // Set current statement position to pos.
-  bool RecordStatementPosition(int pos);
+  void RecordStatementPosition(int pos);
 
  private:
   // Write recorded positions to relocation information.
-  bool WriteRecordedPositions();
+  void WriteRecordedPositions();
 
   Assembler* assembler_;
 
   int current_position_;
   int written_position_;
 
   int current_statement_position_;
   int written_statement_position_;
 
   DISALLOW_COPY_AND_ASSIGN(AssemblerPositionsRecorder);
@@ skipping 167 matching lines @@
     std::vector<ConstantPoolEntry> shared_entries;
   };
 
   Label emitted_label_;  // Records pc_offset of emitted pool
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_ASSEMBLER_H_