leak checking on attach or core dump from native run

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on November 14, 2011 20:01:54_

just an idea noted long ago: for apps using standard glibc malloc or
standard Windows heap, it would be possible to have a tool that attaches to
a native app, walks the heap, and then does a leak scan. the same could be
done on a core dump. there would be no stack zeroing or definedness info
so it would not be as accurate.

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=686_