show heap usage by app module

_From [derek.br...@gmail.com](https://code.google.com/u/117968039472581148324/) on December 10, 2010 19:52:19_

PR 557069

we thought about showing heap usage by app module when we first discussed
how to visualize heap usage. initially it would be simplest to avoid any
changes in data gathering and use the top callstack frame's source file or
something, skipping C++ new frames. due to different layers of custom
wrappers we could try to do dataflow analysis to figure out the end of
wrappers (called Adaptive Partial Call Chain identification in a recent CGO
paper) but let's start simple: and since this can be user-directed we may
never need advanced automatation.

may want app file, or "logical components", instead

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=227_