c-parser.c (c_parser_omp_context_selector): Don't require score argument to fit into shwi, just to be INTEGER_CST.

	* c-parser.c (c_parser_omp_context_selector): Don't require score
	argument to fit into shwi, just to be INTEGER_CST.  Diagnose
	negative score.

	* parser.c (cp_parser_omp_context_selector): Don't require score
	argument to fit into shwi, just to be INTEGER_CST.  Diagnose
	negative score.
	* pt.c (tsubst_attribute): Likewise.

	* c-c++-common/gomp/declare-variant-2.c: Add test for non-integral
	score and for negative score.
	* c-c++-common/gomp/declare-variant-3.c: Add test for zero score.
	* g++.dg/gomp/declare-variant-8.C: Add test for negative and zero
	scores.

From-SVN: r278204