Remove some leftovers of full-codegen's generators implementation.

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 1963 matching lines @@
   void rorxq(Register dst, Register src, byte imm8);
   void rorxq(Register dst, const Operand& src, byte imm8);
   void rorxl(Register dst, Register src, byte imm8);
   void rorxl(Register dst, const Operand& src, byte imm8);
 
   // Check the code size generated from label to here.
   int SizeOfCodeGeneratedSince(Label* label) {
     return pc_offset() - label->pos();
   }
 
-  // Mark generator continuation.
-  void RecordGeneratorContinuation();
-
   // Mark address of a debug break slot.
   void RecordDebugBreakSlot(RelocInfo::Mode mode);
 
   // Record a comment relocation entry that can be used by a disassembler.
   // Use --code-comments to enable.
   void RecordComment(const char* msg);
 
   // Record a deoptimization reason that can be used by a log or cpu profiler.
   // Use --trace-deopt to enable.
   void RecordDeoptReason(DeoptimizeReason reason, SourcePosition position,
@@ skipping 534 matching lines @@
   Assembler* assembler_;
 #ifdef DEBUG
   int space_before_;
 #endif
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_X64_ASSEMBLER_X64_H_