Fix supertypes for reflected Java classes, always include j.l.Object

equals/hashCode/toString had not appeared in Java classes' "members" because of
this

compiler/testData/codegen/boxWithJava/reflection/javaClassGetFunctions/J.java

@@ -0,0 +1,10 @@
+public class J {
+    public J() {
+    }
+
+    public void member(String s) {
+    }
+
+    public static void staticMethod(int x) {
+    }
+}