[SLC] make INSTANCE field for object public

^KT-56441 Fixed

compiler/testData/asJava/lightClasses/lightClassByPsi/companionDuplication.descriptors.java

@@ -0,0 +1,20 @@
+public final class C /* C*/ {
+  @org.jetbrains.annotations.NotNull()
+  public static final C.Companion Companion;
+
+  public  C();//  .ctor()
+
+  class Companion ...
+
+  class Factory ...
+}
+
+public static final class Companion /* C.Companion*/ {
+  private  Companion();//  .ctor()
+
+  public final void bar();//  bar()
+}
+
+public static final class Factory /* C.Factory*/ {
+  private  Factory();//  .ctor()
+}