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/j+k/recursiveRawUpperBound.kt

@@ -1,10 +1,10 @@
 // FILE: Bad.java
 
-class Bad<T extends Bad> {}
+public class Bad<T extends Bad> {}
 
 // FILE: X.java
 
-class X {
+public class X {
   Bad foo() {return null;}
 }