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/imports/ImportProtectedClass.kt

@@ -7,8 +7,8 @@ open class Foo {
 }
 
 class Bar: Foo() {
-    fun foo(): Nested? = null
+    protected fun foo(): Nested? = null
 }
 
-fun foo(): <!INVISIBLE_REFERENCE!>Nested<!>? = null
-fun bar(): p.Foo.<!INVISIBLE_REFERENCE!>Nested<!>? = null
+private fun foo(): <!INVISIBLE_REFERENCE!>Nested<!>? = null
+private fun bar(): p.Foo.<!INVISIBLE_REFERENCE!>Nested<!>? = null

compiler/testData/diagnostics/tests/imports/ImportProtectedClass.txt

@@ -1,13 +1,13 @@
 package
 
 package p {
-    public fun bar(): p.Foo.Nested?
-    public fun foo(): p.Foo.Nested?
+    private fun bar(): p.Foo.Nested?
+    private fun foo(): p.Foo.Nested?
 
     public final class Bar : p.Foo {
         public constructor Bar()
         public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-        public final fun foo(): p.Foo.Nested?
+        protected final fun foo(): p.Foo.Nested?
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
     }

compiler/testData/diagnostics/tests/imports/PackageLocalClassReferencedError.kt

@@ -8,4 +8,4 @@ package a
 
 import pack1.*
 
-class X : <!INVISIBLE_REFERENCE, INVISIBLE_MEMBER!>SomeClass<!>()
+private class X : <!INVISIBLE_REFERENCE, INVISIBLE_MEMBER!>SomeClass<!>()

compiler/testData/diagnostics/tests/imports/PackageLocalClassReferencedError.txt

@@ -2,7 +2,7 @@ package
 
 package a {
 
-    public final class X : pack1.SomeClass {
+    private final class X : pack1.SomeClass {
         public constructor X()
         invisible_fake open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         invisible_fake open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int

compiler/testData/diagnostics/tests/imports/PrivateClassReferencedError.kt

@@ -11,4 +11,4 @@ package a
 
 import pack1.SomeClass.*
 
-class X : <!INVISIBLE_REFERENCE, INVISIBLE_MEMBER, FINAL_SUPERTYPE!>N<!>()
+private class X : <!INVISIBLE_REFERENCE, INVISIBLE_MEMBER, FINAL_SUPERTYPE!>N<!>()

compiler/testData/diagnostics/tests/imports/PrivateClassReferencedError.txt

@@ -2,7 +2,7 @@ package
 
 package a {
 
-    public final class X : pack1.SomeClass.N {
+    private final class X : pack1.SomeClass.N {
         public constructor X()
         invisible_fake open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
         invisible_fake open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int