re PR tree-optimization/83176 ([graphite] ICE in set_codegen_error, at graphite-isl-ast-to-gimple.c:206)

2018-01-24  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/83176
	* tree-chrec.c (chrec_fold_plus_1): Handle (signed T){(T) .. }
	operands.

	* gcc.dg/graphite/pr83176.c: New testcase.

From-SVN: r257013