New J2K: Split old j2k and new j2k tests

nj2k/testData/newJ2k/assignmentExpression/nullability-settings.kt

@@ -0,0 +1,10 @@
+// !forceNotNullTypes: false
+// !specifyLocalVariableTypeByDefault: true
+
+internal class Foo {
+    fun foo(o: HashSet<*>) {
+        val o2: HashSet<*> = o
+        var foo: Int = 0
+        foo = o2.size
+    }
+}