Consolidate SMI functions into one area for X64

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index d9fb3731a39f6eb17bc8c0b3fac1bfc6fab1472e..8e30981833acff2e6caac0b8ddf2b0276d51c9de 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -375,6 +375,11 @@ class MacroAssembler: public Assembler {
   // ---------------------------------------------------------------------------
   // Smi tagging, untagging and operations on tagged smis.
 
+  // Support for constant splitting.
+  bool IsUnsafeInt(const int32_t x);
+  void SafeMove(Register dst, Smi* src);
+  void SafePush(Smi* src);
+
   void InitializeSmiConstantRegister() {
     movq(kSmiConstantRegister,
          reinterpret_cast<uint64_t>(Smi::FromInt(kSmiConstantRegisterValue)),
@@ -782,11 +787,6 @@ class MacroAssembler: public Assembler {
   // Move if the registers are not identical.
   void Move(Register target, Register source);
 
-  // Support for constant splitting.
-  bool IsUnsafeInt(const int x);
-  void SafeMove(Register dst, Smi* src);
-  void SafePush(Smi* src);
-
   // Bit-field support.
   void TestBit(const Operand& dst, int bit_index);