Quoc Peyrot <chojin@lrde.epita.fr>,

	Quoc Peyrot <chojin@lrde.epita.fr>,
	Robert Anisko <anisko_r@lrde.epita.fr>
* data/lalr1.cc (parse::yyerrlab1): When popping the stack, stop
when the stacks contain one element, as the loop would otherwise
free the last state, and then use the top state (the one we just
popped).  This means that the initial elements will not be freed
explicitly, as is the case in yacc.c; it is not a problem, as
these elements have fake values.