on private library RtlDestroyHeap, free all interior blocks

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on February 16, 2011 18:21:35_

I extended private library isolation to cover more than just the default heap, but one aspect takes more than a wrapper to implement: on RtlDestroyHeap we need to iterate over all blocks in the heap and free them.
would have to keep a list of blocks.
For now we assume all private heaps practice individual dealloc
instead of whole-pool-free, which is the case for things like
kernel32!_crtheap.

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=385_