add test for private in file

compiler/testData/diagnostics/tests/scopes/visibility3.kt

@@ -0,0 +1,47 @@
+// !DIAGNOSTICS: -UNUSED_VARIABLE
+
+//FILE:file1.kt
+package a
+
+private open class A {
+    fun bar() {}
+}
+
+private var x: Int = 10
+
+private fun foo() {}
+
+private fun bar() {
+    val y = x
+    x = 20
+}
+
+fun makeA() = A()
+
+private object PO {}
+
+//FILE:file2.kt
+package a
+
+fun test() {
+    val y = makeA()
+    y.<!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>bar<!>()
+    <!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>foo<!>()
+
+    val u : <!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>A<!> = <!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>A<!>()
+
+    val z = <!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>x<!>
+    <!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>x<!> = 30
+
+    val po = <!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>PO<!>
+}
+
+class B : <!ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE, ACCESS_TO_PRIVATE_TOP_LEVEL_FROM_ANOTHER_FILE!>A<!>() {}
+
+class Q {
+    class W {
+        fun foo() {
+            val y = makeA() //assure that 'makeA' is visible
+        }
+    }
+}