re PR c++/7874 (g++ finds friend functions defined in class-definition but not declared in the enclosing namespace)

./	PR g++/7874
	* c.opt (ffriend-injection): New C++ option.
	* doc/invoke.texi (Option Summary): Mention -ffriend-injection.
	(C++ Dialect Options): Document -ffriend-injection.
cp/
	PR g++/7874
	* cp-tree.h (struct lang_decl_flags): Add hidden_friend_p
	bitfield.  Make dummy bitfield one bit smaller.
	(DECL_HIDDEN_FRIEND_P): Define.
	(pushdecl_maybe_friend): Declare.
	(pushdecl_top_level_maybe_friend): Declare.
	* decl.c (duplicate_decls): Add newdecl_is_friend parameter.
	Change prototype and all callers.  Add assertion that a
	DECL_ARTIFICIAL FUNCTION_DECL is not DECL_HIDDEN_FRIEND_P.  Set
	DECL_ANTICIPATED and DECL_HIDDEN_FRIEND_P in duplicated decl if
	appropriate.
	* name-lookup.c (supplement_binding): Don't ignore a
	DECL_HIDDEN_FRIEND_P.
	(pushdecl_maybe_friend): Break out contents of pushdecl.  Add
	is_friend parameter.  Set DECL_ANTICIPATED and
	DECL_HIDDEN_FRIEND_P for a friend function.
	(pushdecl): Just call pushdecl_maybe_friend.
	(pushdecl_with_scope): Add is_friend parameter.  Change prototype
	and all callers.
	(pushdecl_namespace_level): Likewise.
	(push_overloaded_decl): Likewise.  Check DECL_HIDDEN_FRIEND_P as
	well as DECL_ANTICIPATED when checking for a builtin.
	(do_nonmember_using_decl): Check DECL_HIDDEN_FRIEND_P as well as
	DECL_ANTICIPATED when checking for a builtin.
	(do_nonmember_using_decl): Likewise.
	(pushdecl_top_level_1): Add is_friend parameter.  Change all
	callers.
	(pushdecl_top_level_maybe_friend): New function.
	(remove_hidden_names): New function.
	(struct arg_lookup): Add args field.
	(friend_of_associated_class_p): New static function.
	(arg_assoc_namespace): Ignore hidden functions which are not
	friends of an associated class of some argument.
	(lookup_arg_dependent): Remove hidden functions from list passed
	in.  Initialize k.args.
	* name-lookup.h (remove_hidden_names): Declare.
	* friend.c (do_friend): Call pushdecl_maybe_friend instead of
	pushdecl.
	* call.c (add_function_candidate): Change DECL_ANTICIPATED test to
	an assertion, with a check for DECL_HIDDEN_FRIEND_P.
	(build_new_function_call): Add koenig_p parameter.  Change
	prototype and callers.
	* pt.c (register_specialization): Add is_friend parameter.  Change
	all callers.
	(push_template_decl_real): Change is_friend parameter to bool.
	Change prototype and all callers.
	(tsubst_friend_class): Call pushdecl_top_level_maybe_friend
	instead of pushdecl_top_level.
testsuite/
	PR g++/7874
	* g++.dg/lookup/friend7.C: New test.
	* g++.dg/lookup/friend8.C: New test.
	* g++.dg/parse/defarg4.C: Add a parameter to the friend function,
	so that it will be found via argument dependent lookup.
	* g++.old-deja/g++.brendan/crash56.C: Don't expect errors for
	friend functions which will no longer be found.
	* g++.old-deja/g++.jason/friend.C: Add a parameter to the friend
	function g, so that it will be found via argument dependent
	lookup.
	* g++.old-deja/g++.jason/scoping15.C: Use -ffriend-injection.
	* g++.old-deja/g++.mike/net43.C: Likewise.

From-SVN: r104188