A64: Update DoAllocate() to use a W register for the size

src/a64/macro-assembler-a64.cc

 // Copyright 2013 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 3053 matching lines @@
       // We apply salt to the original zap value to easily spot the values.
       Mov(result, (kDebugZapValue & ~0xffL) | 0x11L);
       Mov(scratch1, (kDebugZapValue & ~0xffL) | 0x21L);
       Mov(scratch2, (kDebugZapValue & ~0xffL) | 0x21L);
     }
     B(gc_required);
     return;
   }
 
   ASSERT(!AreAliased(object_size, result, scratch1, scratch2, Tmp0(), Tmp1()));
-  ASSERT(object_size.Is64Bits() && result.Is64Bits() && scratch1.Is64Bits() &&
+  ASSERT(result.Is64Bits() && scratch1.Is64Bits() &&
          scratch2.Is64Bits() && Tmp0().Is64Bits() && Tmp1().Is64Bits());
 
   // Check relative positions of allocation top and limit addresses.
   // The values must be adjacent in memory to allow the use of LDP.
   ExternalReference heap_allocation_top =
       AllocationUtils::GetAllocationTopReference(isolate(), flags);
   ExternalReference heap_allocation_limit =
       AllocationUtils::GetAllocationLimitReference(isolate(), flags);
   intptr_t top = reinterpret_cast<intptr_t>(heap_allocation_top.address());
   intptr_t limit = reinterpret_cast<intptr_t>(heap_allocation_limit.address());
@@ skipping 1828 matching lines @@
   }
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_A64