re PR bootstrap/80887 (gnat bootstrap fails at s-regpat.o: raised STORAGE_ERROR : stack overflow or erroneous memory access)

2017-06-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/80887
        c/
	* gimple-parser.c (c_parser_gimple_postfix_expression): Handle
	negated _Literals to parse _Literal (int) -1.

	* tree-ssa-sccvn.c (mprts_hook_cnt): New global.
	(vn_lookup_simplify_result): Allow only mprts_hook_cnt succesful
	simplified lookups, then reset mprts_hook.
	(vn_nary_build_or_lookup_1): Set mprts_hook_cnt to 9 before
	simplifying.
	(try_to_simplify): Likewise.

	* gcc.dg/tree-ssa/pr80887.c: New testcase.

From-SVN: r249373