Specify the type of scop->region

Specify the type of scop->region

Changing the type of scop::region from void* to sese, as this is
the only type assigned to scop::region for now. No functional changes intended.
Passes regtest and bootstrap.

gcc/ChangeLog:

2015-08-17  Aditya Kumar  <aditya.k7@samsung.com>

        * graphite-poly.c: Change type of region from void* to sese.
        * graphite-poly.h (struct scop): Changing the type of scop::region
	from void* to sese. Change accessor macro accordingly.
        * graphite-sese-to-poly.c (extract_affine_chrec): Use accessor macro.

From-SVN: r227151