Conversion operators have a special name

	Conversion operators have a special name
	* cp-tree.h (CPTI_CONV_OP_MARKER, CPTI_CONV_OP_IDENTIFIER): New.
	(conv_op_marker, conv_op_identifier): New.
	(CLASSTYPE_FIRST_CONVERSION_SLOT): Delete.
	* decl.c (initialize_predefined_identifiers): Add
	conv_op_identifier.
	(cxx_init_decl_processing): Create conv_op_marker.
	* decl2.c (check_classfn): Lookup conv-ops by name.
	* class.c (add_method): Use conv_op_identifier & conv_op_marker.
	(resort_type_method_vec): Don't skip conv-ops.
	(finish_struct_methods, warn_hidden): Likewise.
	* name-lookup.h (lookup_all_conversions): Delete.
	* name-lookup.c (lookup_conversion_operator): Replace with ...
	(extract_conversion_operator): ... this.
	(lookup_fnfields_slot_nolazy): Find conv-ops by name.
	(lookup_all_conversions): Delete.
	* pt.c (check_explicit_specialization): Find conv-ops by name.
	* search.c (lookup_conversions_r): Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@251348 138bc75d-0d04-0410-961f-82ee72b054a4