Update the gap resolver to support Smi constants.

src/x64/lithium-gap-resolver-x64.cc

 // Copyright 2011 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 177 matching lines @@
       ASSERT(destination->IsStackSlot());
       Operand dst = cgen_->ToOperand(destination);
       __ movq(kScratchRegister, src);
       __ movq(dst, kScratchRegister);
     }
 
   } else if (source->IsConstantOperand()) {
     LConstantOperand* constant_source = LConstantOperand::cast(source);
     if (destination->IsRegister()) {
       Register dst = cgen_->ToRegister(destination);
-      if (cgen_->IsInteger32Constant(constant_source)) {
+      if (cgen_->IsSmiConstant(constant_source)) {
+        __ Move(dst, cgen_->ToSmi(constant_source));
+      } else if (cgen_->IsInteger32Constant(constant_source)) {
         __ movl(dst, Immediate(cgen_->ToInteger32(constant_source)));
       } else {
         __ LoadObject(dst, cgen_->ToHandle(constant_source));
       }
     } else {
       ASSERT(destination->IsStackSlot());
       Operand dst = cgen_->ToOperand(destination);
-      if (cgen_->IsInteger32Constant(constant_source)) {
+      if (cgen_->IsSmiConstant(constant_source)) {
+        __ Move(dst, cgen_->ToSmi(constant_source));
+      } else if (cgen_->IsInteger32Constant(constant_source)) {
         // Zero top 32 bits of a 64 bit spill slot that holds a 32 bit untagged
         // value.
         __ movq(dst, Immediate(cgen_->ToInteger32(constant_source)));
       } else {
         __ LoadObject(kScratchRegister, cgen_->ToHandle(constant_source));
         __ movq(dst, kScratchRegister);
       }
     }
 
   } else if (source->IsDoubleRegister()) {
@@ skipping 96 matching lines @@
       moves_[i].set_source(source);
     }
   }
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64