* data/push.c (yypstate): Add typedef, and update all uses of

struct yypstate to just yypstate.
* tests/calc.at (_AT_DATA_CALC_Y): Update here as well.

tests/calc.at

@@ -338,7 +338,7 @@ main (int argc, const char **argv)
 [  yydebug = 1;])])[
 ]AT_PUSH_IF([
   {
-    struct yypstate *pstate = yypstate_new ();
+    yypstate *pstate = yypstate_new ();
     YYSTYPE my_lval;
     ]AT_LOCATION_IF([YYLTYPE my_lloc;])[
     do {