Fix bug in edge case in populating PointerMaps

src/lithium-allocator.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 1400 matching lines @@
       int safe_point = map->lithium_position();
 
       // The safe points are sorted so we can stop searching here.
       if (safe_point - 1 > end) break;
 
       // Advance to the next active range that covers the current
       // safe point position.
       LifetimePosition safe_point_pos =
           LifetimePosition::FromInstructionIndex(safe_point);
       LiveRange* cur = range;
-      while (cur != NULL && !cur->Covers(safe_point_pos.PrevInstruction())) {
+      while (cur != NULL && !cur->Covers(safe_point_pos)) {
         cur = cur->next();
       }
       if (cur == NULL) continue;
 
       // Check if the live range is spilled and the safe point is after
       // the spill position.
       if (range->HasAllocatedSpillOperand() &&
           safe_point >= range->spill_start_index()) {
         TraceAlloc("Pointer for range %d (spilled at %d) at safe point %d\n",
                    range->id(), range->spill_start_index(), safe_point);
@@ skipping 685 matching lines @@
     LiveRange* current = live_ranges()->at(i);
     if (current != NULL) current->Verify();
   }
 }
 
 
 #endif
 
 
 } }  // namespace v8::internal