This fixes bootstrap of GCC with BOOT_CFLAGS="-g -O2 -fgraphite-identity
-floop-nest-optimize -floop-block -floop-interchange -floop-strip-mine".  It
passes regstrap on amd64-linux.  A previous change
(https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=213816), replaced
isl_int with isl_val because isl_int would be deprecated. Since isl_val has
stricter checks, it exposed the bug.  In the test case (isl_set_max_val) would
return infinity which would remain unchecked.  We now check if the value
returned is an integer or not, and bail out if it isn't.  The other problem was
that we were allowing all kinds of data-refs in a scop.  Now we discard a scop
if it has any date-ref other than (ARRAY_REF, MEM_REF, COMPONENT_REF).

	PR middle-end/61929
	* graphite-dependences.c (add_pdr_constraints): Renamed
	pdr->extent to pdr->subscript_sizes.
	* graphite-interchange.c (build_linearized_memory_access): Add
	back all gcc_assert's that the "isl_int to isl_val conversion"
	patch has removed.  Refactored.
	(pdr_stride_in_loop): Renamed pdr->extent to pdr->subscript_sizes.
	* graphite-poly.c (new_poly_dr): Same.
	(free_poly_dr): Same.
	* graphite-poly.h (struct poly_dr): Same.
	* graphite-scop-detection.c (stmt_has_simple_data_refs_p): Ignore
	all data references other than ARRAY_REF, MEM_REF, and COMPONENT_REF.
	* graphite-scop-detection.h: Fix space.
	* graphite-sese-to-poly.c (build_pbb_scattering_polyhedrons): Add
	back all gcc_assert's removed by a previous patch.
	(wrap): Remove the_isl_ctx global variable that the same patch has
	added.
	(build_loop_iteration_domains): Same.
	(add_param_constraints): Same.
	(pdr_add_data_dimensions): Same.  Refactored.
	(build_poly_dr): Renamed extent to subscript_sizes.

testsuite/
	PR middle-end/61929
	* gcc.dg/graphite/pr61929.c: New.

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

From-SVN: r225942