handling loops
---------------

There are two cases for handling loops: 

      1) loops that contain barriers
      2) loops that do not contain barriers

1) Is handled by adding implicit barriers before the loop and replicating
the header and the body separately (Carlos please clarify the details).

2) Is handled as a single ParallelRegion. The whole loop is replicated.
In order for this to work, a dummy block is inserted before the loop in
case the loop preheader contains a barrier. 

The dummy block and the implicit barriers in case of barriers inside the
loop are added in LoopBarriers.cc.


