DEADLOCK: fork from multi-threaded parent => locks inconsistent

_From [derek.br...@gmail.com](https://code.google.com/u/117968039472581148324/) on December 01, 2009 11:49:58_

when a multi-threaded process forks, the fork child is alone in its new
process but other threads could have held locks at the fork point. we need
to have a way to iterate over all locks held in release build and free them.

I added cleanup of other thread data structs as part of issue #237

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=239_