Warnings about type tags that are used in printer and dtors, but not
for symbols?
-** YYPRINT
-glr.c inherits its symbol_print function from c.m4, which supports
-YYPRINT. But to use YYPRINT yytoknum is needed, which not defined by
-glr.c.
-
-Anyway, IMHO YYPRINT is obsolete and should be restricted to yacc.c.
-
** YYERRCODE
Defined to 256, but not used, not documented. Probably the token
number for the error token, which POSIX wants to be 256, but which