investigate addressable bytes in heap but not in chunk

_From [derek.br...@gmail.com](https://code.google.com/u/117968039472581148324/) on December 10, 2010 17:58:05_

PR 484550

During leak scanning, I'm seeing defined bytes in heap regions that aren't
in allocated chunk. My old leak checking also found bytes inside heap
regions that were not UNADDR but I don't know how often those were not in
chunks, and most of those were from UNADDR errors that we then marked as
defined. This may well be some inconsistency that should be fixed so we
should investigate.

This assert is the one that fires. I've relaxed it for now.

```
ASSERT(!is_in_heap_region(pointer) ||
shadow_get_byte(pointer) == SHADOW_UNADDRESSABLE,
"heap data struct inconsistency");
```

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=154_