update required isl version

update required isl version

we check for a the isl compute timeout function added in isl 0.13.
That means GCC could still be configured with isl 0.13, 0.14, and 0.15.

	* config/isl.m4 (ISL_CHECK_VERSION): Check for
	isl_ctx_get_max_operations.
	* configure: Regenerate.

	gcc/
	* config.in: Regenerate.
	* configure: Regenerate.
	* configure.ac: Remove checks for functions that exist in isl 0.13 or
	later.
	* graphite-isl-ast-to-gimple.c: Remove #ifdefs and code for isl 0.12.
        * graphite-optimize-isl.c: Same.
	* graphite-poly.c: Same.
	* graphite-sese-to-poly.c: Same.
	* graphite.h: Add comment for isl 0.14.
	* toplev.c (print_version): Print isl version.

Co-Authored-By: Sebastian Pop <s.pop@samsung.com>
From-SVN: r231706