PR c++/27665
	* parser.c (cp_parser_unqualified_id): Use constructor_name_p to
	identify destructors.
	(cp_parser_nested_name_specifier_opt): Remove invalid
	optimization.
	(cp_parser_template_id): Refine heuristic for determining whether
	we are entering a scope.
	PR c++/27665
	* g++.dg/template/crash52.C: New test.

From-SVN: r114669