Remove unused 'unsafe smi' code on x64.

src/x64/macro-assembler-x64.h

 // Copyright 2009 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 356 matching lines @@
   // power of two to multiply the index value by (e.g.
   // to index by smi-value * kPointerSize, pass the smi and kPointerSizeLog2).
   // The returned index register may be either src or dst, depending
   // on what is most efficient. If src and dst are different registers,
   // src is always unchanged.
   SmiIndex SmiToIndex(Register dst, Register src, int shift);
 
   // Converts a positive smi to a negative index.
   SmiIndex SmiToNegativeIndex(Register dst, Register src, int shift);
 
-  bool IsUnsafeSmi(Smi* value);
-  void LoadUnsafeSmi(Register dst, Smi* source);
+  // Basic Smi operations.
+  void Move(Register dst, Smi* source) {
+    Set(dst, reinterpret_cast<int64_t>(source));
+  }
 
-  // Basic Smi operations.
-  void Move(Register dst, Smi* source);
-  void Move(const Operand& dst, Smi* source);
+  void Move(const Operand& dst, Smi* source) {
+    Set(dst, reinterpret_cast<int64_t>(source));
+  }
+
   void Push(Smi* smi);
   void Test(const Operand& dst, Smi* source);
 
   // ---------------------------------------------------------------------------
   // Macro instructions
 
   // Load a register with a long value as efficiently as possible.
   void Set(Register dst, int64_t x);
   void Set(const Operand& dst, int64_t x);
 
   // Handle support
-  bool IsUnsafeSmi(Handle<Object> value) {
-    return IsUnsafeSmi(Smi::cast(*value));
-  }
-
-  void LoadUnsafeSmi(Register dst, Handle<Object> source) {
-    LoadUnsafeSmi(dst, Smi::cast(*source));
-  }
-
   void Move(Register dst, Handle<Object> source);
   void Move(const Operand& dst, Handle<Object> source);
   void Cmp(Register dst, Handle<Object> source);
   void Cmp(const Operand& dst, Handle<Object> source);
   void Push(Handle<Object> source);
 
   // Control Flow
   void Jump(Address destination, RelocInfo::Mode rmode);
   void Jump(ExternalReference ext);
   void Jump(Handle<Code> code_object, RelocInfo::Mode rmode);
@@ skipping 286 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_MACRO_ASSEMBLER_X64_H_