* tests/conflicts.at (%nonassoc and eof): Don't exit with status

1 on syntax error; just let yyparse do its thing.
* tests/glr-regression.at (Badly Collapsed GLR States): Likewise.
* tests/torture.at (AT_DATA_STACK_TORTURE): Likewise.
(Exploding the Stack Size with Alloca):
(Exploding the Stack Size with Malloc):
Expect exit status 2, not 1, since the parser is supposed to blow
its stack.  Problem reported by twlevo@xs4all.nl.

tests/glr-regression.at

@@ -74,7 +74,6 @@ int
 yyerror (char const *msg)
 {
   fprintf (stderr, "%s\n", msg);
-  exit (4);
 }