Add allocation support to x64 macro assembler

src/ia32/macro-assembler-ia32.cc

 // Copyright 2006-2008 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 651 matching lines @@
 void MacroAssembler::AllocateObjectInNewSpace(
     int object_size,
     Register result,
     Register result_end,
     Register scratch,
     Label* gc_required,
     bool result_contains_top_on_entry) {
   ASSERT(!result.is(result_end));
 
   // Load address of new object into result.
-  ExternalReference new_space_allocation_limit =
-      ExternalReference::new_space_allocation_limit_address();
   LoadAllocationTopHelper(result,
                           result_end,
                           scratch,
                           result_contains_top_on_entry);
 
   // Calculate new top and bail out if new space is exhausted.
+  ExternalReference new_space_allocation_limit =
+      ExternalReference::new_space_allocation_limit_address();
   lea(result_end, Operand(result, object_size));
   cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
   j(above, gc_required, not_taken);
 
   // Update allocation top.
   UpdateAllocationTopHelper(result_end, scratch);
 }
 
 
 void MacroAssembler::AllocateObjectInNewSpace(
@@ skipping 485 matching lines @@
   // Indicate that code has changed.
   CPU::FlushICache(address_, size_);
 
   // Check that the code was patched as expected.
   ASSERT(masm_.pc_ == address_ + size_);
   ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
 }
 
 
 } }  // namespace v8::internal