fix PR68343: disable fuse-*.c tests for isl 0.14 or earlier

The patch disables all fuse-*.c tests when configuring gcc with isl 0.14 or earlier.

ChangeLog:

	* Makefile.in: Regenerate.
	* Makefile.tpl: Export ISLVER.
	* configure: Regenerate.
	* config/isl.m4: Detect isl-0.15.

gcc/

	* Makefile.in: Set ISLVER in site.exp.

gcc/testsuite/

	* gcc.dg/graphite/graphite.exp: Only run the fuse-*.c tests with isl-0.15.

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

From-SVN: r232811