Exposed visibility checking, a set of exposed visibility tests, some test fixes

Effective visibility mechanism introduced.
Local is considered as public, java protected as Kotlin protected, java package private as Kotlin private.

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

@@ -0,0 +1,23 @@
+private interface My
+
+private open class Base
+
+public interface Your: <!EXPOSED_SUPER_INTERFACE!>My<!> {
+    fun <T: Base> foo(): T
+}
+
+public class Derived<<!EXPOSED_TYPE_PARAMETER_BOUND!>T: My<!>>(<!EXPOSED_PARAMETER_TYPE!>val x: My<!>): <!EXPOSED_SUPER_CLASS!>Base()<!> {
+
+    constructor(<!EXPOSED_PARAMETER_TYPE!>xx: My?<!>, <!EXPOSED_PARAMETER_TYPE!>x: My<!>): this(xx ?: x)
+
+    <!EXPOSED_PROPERTY_TYPE!>val y: Base? = null<!>
+
+    val <!EXPOSED_RECEIVER_TYPE!>My<!>.z: Int
+        get() = 42
+
+    fun <!EXPOSED_FUNCTION_RETURN_TYPE!>foo<!>(<!EXPOSED_PARAMETER_TYPE!>m: My<!>): My = m
+
+    fun <!EXPOSED_RECEIVER_TYPE!>My<!>.<!EXPOSED_FUNCTION_RETURN_TYPE!>bar<!>(): My = this
+}
+
+