j2k: flatten test cases and testData directory structure

Move j2k/test/tests -> j2k/tests, j2k/test/testData -> j2k/testData

j2k/testData/fileOrElement/inheritance/openModifier.kt

@@ -0,0 +1,51 @@
+import java.lang.Void
+
+open class A {
+    public open fun f1() {
+    }
+
+    public fun f2() {
+    }
+
+    private fun f3() {
+    }
+}
+
+open class B : A() {
+    override fun f1() {
+        super.f1()
+    }
+}
+
+class C : B() {
+    override fun f1() {
+        super.f1()
+    }
+}
+
+trait I {
+    public fun f()
+}
+
+class D : I {
+    override fun f() {
+    }
+}
+
+abstract class E {
+    abstract fun f1()
+    open fun f2() {
+    }
+
+    fun f3() {
+    }
+}
+
+class F : E() {
+    override fun f1() {
+    }
+
+    override fun f2() {
+        super.f2()
+    }
+}