X64: Change kSmiConstantRegister to r12.

src/x64/register-allocator-x64-inl.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 42 matching lines @@
     3,   // rdx
     1,   // rbx
     -1,  // rsp  Stack pointer.
     -1,  // rbp  Frame pointer.
     -1,  // rsi  Context.
     4,   // rdi
     5,   // r8
     6,   // r9
     -1,  // r10  Scratch register.
     8,   // r11
-    9,   // r12
+    -1,  // r12  Smi constant.
     -1,  // r13  Roots array.  This is callee saved.
     7,   // r14
-    -1   // r15  Smi constant register.
+    9    // r15
   };
   return kNumbers[reg.code()];
 }
 
 
 Register RegisterAllocator::ToRegister(int num) {
   ASSERT(num >= 0 && num < kNumRegisters);
   const Register kRegisters[] =
-      { rax, rbx, rcx, rdx, rdi, r8, r9, r14, r11, r12 };
+      { rax, rbx, rcx, rdx, rdi, r8, r9, r14, r11, r15 };
   return kRegisters[num];
 }
 
 
 void RegisterAllocator::Initialize() {
   Reset();
   // The non-reserved rdi register is live on JS function entry.
   Use(rdi);  // JS function.
 }
 } }  // namespace v8::internal
 
 #endif  // V8_X64_REGISTER_ALLOCATOR_X64_INL_H_