Effective visibility: java package-private is now considered as equivalent to Kotlin internal #KT-9755 Fixed

compiler/testData/diagnostics/tests/exposed/packagePrivate.kt

@@ -0,0 +1,35 @@
+// FILE: test/My.java
+
+package test;
+
+class Internal {}
+
+public class My {
+    static public Internal foo() { return new Internal(); }
+}
+
+// FILE: test/His.kt
+
+package test
+
+class His {
+    // Ok: private vs package-private
+    private fun private() = My.foo()
+    // Ok: internal vs package-private in same package
+    internal fun internal() = My.foo()
+    // Error: protected vs package-private
+    protected fun <!EXPOSED_FUNCTION_RETURN_TYPE!>protected<!>() = My.foo()
+    // Error: public vs package-private
+    fun <!EXPOSED_FUNCTION_RETURN_TYPE!>public<!>() = My.foo()
+}
+
+// FILE: other/Your.kt
+
+package other
+
+import test.My
+
+class Your {
+    // Ok but dangerous: internal vs package-private in different package
+    internal fun bar() = My.foo()
+}