* c-decl.c (last_function_parms, last_function_parm_tags)

	(last_function_parm_others, current_function_parms)
	(current_function_parm_tags, current_function_parm_others):
	Delete.
	(ARG_INFO_PARMS, ARG_INFO_TAGS, ARG_INFO_TYPES, ARG_INFO_OTHERS):
	New macros.
	(grokdeclarator): For function definitions, save the arg-info
	block from the declarator in DECL_ARGUMENTS.
	(grokparms): Do not write to last_function_parm*.  Use ARG_INFO_*
	macros to operate on arg-info block.  Can assume ARG_INFO_PARMS
	contains only PARM_DECLs.  Improve diagnostics.
	(get_parm_info): Use ARG_INFO_* macros.  Improve comments and
	diagnostics.  Disable some expensive checks if not ENABLE_CHECKING.
	(store_parm_decls_newstyle): Take the function to operate on,
	and an arg-info block, as arguments; don't get anything from
	current_function_* globals.
	(store_parm_decls_oldstyle): Likewise.
	(store_parm_decls): Pass fndecl and its arg-info block down to
	store_parm_decls_newstyle/oldstyle.  Send functions with empty
	argument lists through store_parm_decls_newstyle to reduce
	overhead.
	(pushdecl): Comment on the problems with the call to copy_node.
	Clear DECL_ARGUMENTS of the old node after copying it, if it
	is an arg-info block instead of a chain of decls.
	(start_function): Do not manipulate current_function_parm* or
	last_function_parm*.

	* testsuite/gcc.dg/noncompile/incomplete-2.c: Move dg-error to
	proper line.

From-SVN: r79206