tests: use assert instead of plain abort.

* tests/actions.at, tests/calc.at, tests/conflicts.at,
* tests/cxx-type.at, tests/glr-regression.at, tests/input.at,
* tests/named-refs.at, tests/regression.at, tests/torture.at,
* tests/local.at:
Prefer assert to abort.

tests/named-refs.at

@@ -162,10 +162,8 @@ int main (int argc, const char **argv)
     }
   status = yyparse ();
   fclose (input);
-  if (global_result != result)
-    abort ();
-  if (global_count != count)
-    abort ();
+  assert (global_result == result);
+  assert (global_count == count);
   return status;
 }
 ]])