(_AT_CHECK_PRINTER_AND_DESTRUCTOR,

AT_CHECK_PRINTER_AND_DESTRUCTOR): New argument
UNION-FLAG.  All callers changed.
(_AT_CHECK_PRINTER_AND_DESTRUCTOR): Don't assume %union.
Use type char, not unsigned int, when declaring an array of char;
this lets us remove a cast.
(Printers and Destructors): Add non-%union test cases.