Remove the unused support for jump-table switch statements.

src/x64/assembler-x64.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 794 matching lines @@
   void WriteRecordedPositions();
 
   // Writes a doubleword of data in the code stream.
   // Used for inline tables, e.g., jump-tables.
   // void dd(uint32_t data);
 
   // Writes a quadword of data in the code stream.
   // Used for inline tables, e.g., jump-tables.
   // void dd(uint64_t data, RelocInfo::Mode reloc_info);
 
-  // Writes the absolute address of a bound label at the given position in
-  // the generated code. That positions should have the relocation mode
-  // internal_reference!
-  void WriteInternalReference(int position, const Label& bound_label);
-
   int pc_offset() const  { return pc_ - buffer_; }
   int current_statement_position() const { return current_statement_position_; }
   int current_position() const  { return current_position_; }
 
   // Check if there is less than kGap bytes available in the buffer.
   // If this is the case, we need to grow the buffer before emitting
   // an instruction or relocation information.
   inline bool overflow() const { return pc_ >= reloc_info_writer.pos() - kGap; }
 
   // Get the number of bytes available in the buffer.
@@ skipping 205 matching lines @@
  private:
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_ASSEMBLER_X64_H_