Fix building with GCC 3.x

src/mark-compact.cc

 // Copyright 2012 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 559 matching lines @@
   Candidate* least = NULL;
 
   PageIterator it(space);
   if (it.has_next()) it.next();  // Never compact the first page.
 
   while (it.has_next()) {
     Page* p = it.next();
     p->ClearEvacuationCandidate();
 
     if (FLAG_stress_compaction) {
-      int counter = space->heap()->ms_count();
+      unsigned int counter = space->heap()->ms_count();
       uintptr_t page_number = reinterpret_cast<uintptr_t>(p) >> kPageSizeBits;
       if ((counter & 1) == (page_number & 1)) fragmentation = 1;
     } else if (mode == REDUCE_MEMORY_FOOTPRINT) {
       // Don't try to release too many pages.
       if (estimated_release >= ((over_reserved * 3) / 4)) {
         continue;
       }
 
       intptr_t free_bytes = 0;
 
@@ skipping 3558 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal