Add tests.

Author: kaby76

tests/grammars/Up2.g4

@@ -0,0 +1,2 @@
+grammar Up2;
+start: a ( b | c )* d;

tests/grammars/Up3.g4

@@ -0,0 +1,2 @@
+grammar Up3;
+start: a ( v += b )* c;

tests/test.sh

@@ -7,10 +7,18 @@ where=`pwd`
 cd "$where"
 echo "$where"
 cd "$where"
-bash ../find-useless-parentheses.sh grammars/Up1.g4
-if [ $? -ne 0 ]
+failed=0
+for t in grammars/*.g4
+do
+	bash ../find-useless-parentheses.sh $t
+	if [ $? -ne 0 ]
+	then
+		echo Test "'bash ../find-useless-parentheses.sh $t'" failed.
+		failed=1
+	fi
+done
+if [ $failed -ne 0 ]
 then
-	echo Test "'bash ../find-useless-parentheses.sh grammars/Up1.g4'" failed.
 	exit 1
 else
 	exit 0