Star projection information preserved in substitutions

#KT-6700 Fixed

compiler/testData/loadJava/compiledJava/UnboundWildcard.java

@@ -1,5 +1,7 @@
 package test;
 
+import java.util.Collection;
+
 public final class UnboundWildcard {
     public final MyClass<?> foo() {
         throw new UnsupportedOperationException();
@@ -7,4 +9,8 @@ public final class UnboundWildcard {
 
     public interface MyClass<T extends CharSequence> {
     }
+
+    public final Collection<?> collection() {
+        throw new UnsupportedOperationException();
+    }
 }