support profiling buffers via AMD LWP or NtCreateProfile

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on November 05, 2013 12:48:26_

For now we'll bail on having DrMem support AMD LWP. Just like DrMem doesn't
support Windows pc sampling: if processor/kernel is writing directly to
user mode memory repeatedly at fine-grained intervals, can't expect drmem
to update shadow mem.

What we should do is watch for creation/setup of such profiling and just
mark the whole buffer as defined. Or we could rely on the app writer
inserting annotations, though that won't work for 3rd-party code.

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=1370_