MIPS64: Fix ConvertDToI test.

test/cctest/test-code-stubs-mips64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Rrdistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Rrdistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Rrdistributions 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 86 matching lines @@
   }
   __ Call(start, RelocInfo::EXTERNAL_REFERENCE);
   __ bind(&done);
 
   __ Daddu(sp, sp, Operand(kDoubleSize));
 
   // Make sure no registers have been unexpectedly clobbered
   for (--reg_num; reg_num >= 2; --reg_num) {
     Register reg = Register::from_code(reg_num);
     if (!reg.is(destination_reg)) {
-      __ lw(at, MemOperand(sp, 0));
+      __ ld(at, MemOperand(sp, 0));
       __ Assert(eq, kRegisterWasClobbered, reg, Operand(at));
       __ Daddu(sp, sp, Operand(kPointerSize));
     }
   }
 
   __ Daddu(sp, sp, Operand(kDoubleSize));
 
   __ Move(v0, destination_reg);
   Label ok;
   __ Branch(&ok, eq, v0, Operand(zero_reg));
@@ skipping 61 matching lines @@
                                         false));
       RunAllTruncationTests(
           RunGeneratedCodeCallWrapper,
           MakeConvertDToIFuncTrampoline(isolate,
                                         source_registers[s],
                                         dest_registers[d],
                                         true));
     }
   }
 }