properly handle address overflow in stored end addresses

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on June 04, 2013 16:26:24_

This is the DrMem counterpart to DRi#704.

Xref issue #1260 , which solves this for Umbra loops by using closed intervals.

We have many places that compute/pass/store end addresses which need to be changed to either closed intervals or to use the size or to disallow the top of the address space.

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=1261_