[FIR] Check standalone companion object qualifiers are visible

compiler/testData/diagnostics/tests/classObjects/ClassObjectVisibility.fir.kt

@@ -3,9 +3,10 @@ package foo
 fun test() {
   A.d
   A.Companion.<!INVISIBLE_REFERENCE!>f<!>
-  B.D
-  CCC
+  B.<!INVISIBLE_REFERENCE!>D<!>
+  <!INVISIBLE_REFERENCE!>CCC<!>
   CCC.<!INVISIBLE_REFERENCE!>classObjectVar<!>
+  E.F.G
 }
 
 class A() {
@@ -28,3 +29,10 @@ class CCC() {
     val classObjectVar = 3
   }
 }
+
+class E {
+    class F {
+        companion object G
+    }
+    private companion object
+}

compiler/testData/diagnostics/tests/classObjects/ClassObjectVisibility.kt

@@ -6,6 +6,7 @@ fun test() {
   B.<!INVISIBLE_MEMBER!>D<!>
   <!INVISIBLE_MEMBER!>CCC<!>
   CCC.<!INVISIBLE_MEMBER!>classObjectVar<!>
+  E.F.G
 }
 
 class A() {
@@ -28,3 +29,10 @@ class CCC() {
     val classObjectVar = 3
   }
 }
+
+class E {
+    class F {
+        companion object G
+    }
+    private companion object
+}

compiler/testData/diagnostics/tests/classObjects/ClassObjectVisibility.txt

@@ -60,4 +60,32 @@ package foo {
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
         }
     }
+
+    public final class E {
+        public constructor E()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        private companion object Companion {
+            private constructor Companion()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+
+        public final class F {
+            public constructor F()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+            public companion object G {
+                private constructor G()
+                public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+                public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+                public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+            }
+        }
+    }
 }

compiler/testData/diagnostics/tests/classObjects/invisibleClassObjects.fir.diag.txt

@@ -12,6 +12,8 @@
 
 /b.kt:(225,226): error: Cannot access 'class B : Any': it is private in file.
 
+/b.kt:(234,235): error: Cannot access 'companion object Companion : Any': it is private in 'a/C'.
+
 /b.kt:(243,244): error: Cannot access 'class D : Any': it is private in file.
 
 /b.kt:(263,264): error: Cannot access 'class B : Any': it is private in file.

compiler/testData/diagnostics/tests/classObjects/invisibleClassObjects.fir.kt

@@ -41,7 +41,7 @@ import a.<!INVISIBLE_REFERENCE!>D<!>.<!INVISIBLE_REFERENCE!>Companion<!>.quux
 fun test() {
     f(A)
     f(<!INVISIBLE_REFERENCE!>B<!>)
-    f(C)
+    f(<!INVISIBLE_REFERENCE!>C<!>)
     f(<!INVISIBLE_REFERENCE!>D<!>)
 
     A.foo()