[swfinterp] Start working on basic tests

test/swftests/LocalVars.as

@@ -0,0 +1,13 @@
+// input: [1, 2]
+// output: 3
+
+package {
+public class LocalVars {
+    public static function main(a:int, b:int):int{
+        var c:int = a + b + b;
+        var d:int = c - b;
+        var e:int = d;
+        return e;
+    }
+}
+}