* c-exp.y (check_parameter_typelist): New function.

	* c-exp.y (check_parameter_typelist): New function.
	(parameter_typelist): Call it.
	* eval.c (make_params): Handle '(void)' case.
	* gdbtypes.c (lookup_function_type_with_arguments): Handle
	'(void)' case.
testsuite
	* gdb.base/whatis.exp: Add error checks for improper 'void' uses.
	* gdb.base/callfuncs.exp: Add cast-based test.
	* gdb.base/callfuncs.c (voidfunc): New function.