[GSoC 2016]New function pass ScopInfoWrapperPass

This patch adds a new function pass ScopInfoWrapperPass so that the
polyhedral description of a region, the SCoP, can be constructed and
used in a function pass.

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

Differential Revision: http://reviews.llvm.org/D20962