j2k: flatten test cases and testData directory structure

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

j2k/testData/fileOrElement/issues/kt-696.java

@@ -0,0 +1,36 @@
+//file
+package test;
+
+class Base {
+  @Override
+  public int hashCode() {
+    return super.hashCode();
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    return super.equals(o);
+  }
+
+  @Override
+  public String toString() {
+    return super.toString();
+  }
+}
+
+class Child extends Base {
+  @Override
+  public int hashCode() {
+    return super.hashCode();
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    return super.equals(o);
+  }
+
+  @Override
+  public String toString() {
+    return super.toString();
+  }
+}