PR c++/45114 - Support C++11 alias-declaration

PR c++/45114 - Support C++11 alias-declaration

gcc/cp/

	* cp-tree.h (TYPE_DECL_ALIAS_P, TYPE_ALIAS_P)
	(DECL_TYPE_TEMPLATE_P, DECL_ALIAS_TEMPLATE_P): New accessor
	macros.
	(TYPE_TEMPLATE_INFO): Get template info of an alias template
	specializations from its TYPE_DECL.
	(SET_TYPE_TEMPLATE_INFO): Set template info of alias template
	specializations into its TYPE_DECL.
	(DECL_CLASS_TEMPLATE_P): Re-write using the new
	DECL_TYPE_TEMPLATE_P.
	(enum cp_decl_spec): Add new ds_alias enumerator.
	(alias_type_or_template_p, alias_template_specialization_p):
	Declare new functions.
	* parser.c (cp_parser_alias_declaration): New static function.
	(cp_parser_check_decl_spec): Add "using" name for the `alias'
	declspec.
	(cp_parser_type_name): Update comment.  Support simple-template-id
	representing alias template specializations in c++0x mode.
	(cp_parser_qualifying_entity): Update comment.  Use
	cp_parser_type_name.
	(cp_parser_block_declaration): Handle alias-declaration in c++11.
	Update comment.
	(cp_parser_template_id): Handle specializations of alias
	templates.
	(cp_parser_member_declaration): Add alias-declaration production
	to comment.  Support alias-declarations.
	(cp_parser_template_declaration_after_export): Handle alias
	templates in c++11.
	* decl.c (make_typename_type, make_unbound_class_template): Accept
	alias templates.
	(grokdeclarator): Set TYPE_DECL_ALIAS_P on alias
	declarations.
	* decl2.c (grokfield): Move template creation after setting up the
	TYPE_DECL of the alias, so that the TEMPLATE_DECL of the alias
	template actually carries the right type-id of the alias
	declaration.
	* pt.c (alias_type_or_template_p)
	(alias_template_specialization_p): Define new public functions.
	(maybe_process_partial_specialization): Reject partial
	specializations of alias templates.
	(primary_template_instantiation_p): Consider alias template
	instantiations.
	(push_template_decl_real): Assert that TYPE_DECLs of alias
	templates are different from those of class template.  Store
	template info onto the TYPE_DECL of the alias template.
	(convert_template_argument): Strip aliases from template
	arguments.
	(lookup_template_class_1): Handle the creation of the
	specialization of an alias template.
	(tsubst_decl): Create a substituted copy of the TYPE_DECL of an
	member alias template.
	(tsubst): Handle substituting into the type of an alias template.
	Handle substituting UNBOUND_CLASS_TEMPLATE into
	BOUND_TEMPLATE_TEMPLATE_PARM.
	(do_type_instantiation): Better diagnostics when trying to
	explicitely instantiate a non-class template.
	* search.c (lookup_field_1, lookup_field_r): Support looking up
	alias templates.
	* semantics.c (finish_template_type): For instantiations of alias
	templates, return the TYPE_DECL of the actual alias and not the
	one of the aliased type.
	* error.c (dump_alias_template_specialization): New static
	function.
	(dump_type): Handle printing of alias templates and their
	specializations.  templates.
	(dump_aggr_type): For specialization of alias templates, fetch
	arguments from the right place.
	(dump_decl): Print an alias-declaration like `using decl = type;'
	(dump_template_decl):  Support printing of alias templates.

gcc/testsuite/

	* g++.dg/cpp0x/alias-decl-0.C: New test case.
	* g++.dg/cpp0x/alias-decl-1.C: Likewise.
	* g++.dg/cpp0x/alias-decl-3.C: Likewise.
	* g++.dg/cpp0x/alias-decl-4.C: Likewise.
	* g++.dg/cpp0x/alias-decl-6.C: Likewise.
	* g++.dg/cpp0x/alias-decl-7.C: Likewise.
	* g++.dg/cpp0x/alias-decl-8.C: Likewise.
	* g++.dg/cpp0x/alias-decl-9.C: Likewise.
	* g++.dg/cpp0x/alias-decl-10.C: Likewise.
	* g++.dg/ext/alias-decl-attr1.C: Likewise.
	* g++.dg/ext/alias-decl-attr2.C: Likewise.
	* g++.dg/ext/alias-decl-attr3.C: Likewise.
	* g++.dg/ext/alias-decl-attr4.C: Likewise.

From-SVN: r181118