* cp-tree.h (DECL_PARM_LEVEL): New.

	* cp-tree.h (DECL_PARM_LEVEL): New.
	(struct lang_decl_parm): Add level field.
	* name-lookup.c (function_parm_depth): New fn.
	* name-lookup.h: Declare it.
	* parser.c (cp_parser_parameter_declaration_list): Use it.
	* mangle.c (struct globals): Add parm_depth field.
	(write_bare_function_type): Adjust it.
	(write_expression): Include the level delta in PARM_DECL mangling
	for abi >= 6.

	* semantics.c (finish_decltype_type): Remove shortcut for decltype
	of id-expression.
	* mangle.c (write_type) [DECLTYPE_TYPE]: Strip it here for abi < 6.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@170459 138bc75d-0d04-0410-961f-82ee72b054a4