[PATCH] Add register dumping support to SuspendedThreadsList.

[Sergey Matveev]

  The code that uses this class is not supposed to know the order of registers in the array. LSan receives them simply as a blob of uptrs to consume (+ the stack pointer). That way all architecture- and platform-specific stuff is encapsulated in this module, at the expense of making this interface rather LSan-specific (it doesn't seem like anyone else will be using it anytime soon though).

  We could also filter out irrelevant registers here, although I don't see much point in doing that, since they're unlikely to cause trouble.

http://llvm-reviews.chandlerc.com/D593