This patch updates memory management of ScopBuilder class.

  1. SCoP object is not owned by ScopBuilder. It just creates a SCoP and
     hand over ownership through getScop() method.
  2. ScopInfoRegionPass owns the SCoP object for a given region.

Patch by Utpal Bora <cs14mtech11017@iith.ac.in>

Differential Revision: http://reviews.llvm.org/D20912

llvm-svn: 273855