[PATCH] Revert "[PECOFF] Add atoms to the PassManager file"

[Chandler Carruth]

  Also, if you want to change the design of how atoms get added, I really don't see why that should happen in this change.

  It seems much better to revert a change which introduced a regression, and *then* consider new or different designs that would be simpler or more efficient for some reason.

http://llvm-reviews.chandlerc.com/D2069