fix PR67700

The patch makes the detection of scop parameters in parameter_index_in_region a
bit more conservative by discarding scalar variables defined in function of data
references defined in the scop.

2015-09-25  Aditya Kumar  <aditya.k7@samsung.com>
                Sebastian Pop  <s.pop@samsung.com>

                PR tree-optimization/67700
                * graphite-sese-to-poly.c (parameter_index_in_region): Call
                invariant_in_sese_p_rec.
                (extract_affine): Same.
                (rewrite_cross_bb_scalar_deps): Call update_ssa.
                * sese.c (invariant_in_sese_p_rec): Export.  Handle vdefs and vuses.
                * sese.h (invariant_in_sese_p_rec): Declare.

                * testsuite/gcc.dg/graphite/run-id-pr67700.c: New.

Co-Authored-By: Sebastian Pop <s.pop@samsung.com>

From-SVN: r228214