Checked that KT-13766 Fixed by some changes in resolve

#KT-13766 Fixed

idea/testData/editor/optimizeImports/KT13766.kt

@@ -0,0 +1,22 @@
+import java.util.*
+
+class Outer {
+
+    private abstract class Base {
+
+        protected sealed class Sealed {
+            object OOO : Sealed()
+        }
+
+        typealias OOO = Sealed.OOO
+    }
+
+    private class Derived : Base() {
+
+        fun foo(): Sealed {
+            ArrayList<Int>()
+            return OOO
+        }
+
+    }
+}

idea/testData/editor/optimizeImports/KT13766.kt.after

@@ -0,0 +1,22 @@
+import java.util.ArrayList
+
+class Outer {
+
+    private abstract class Base {
+
+        protected sealed class Sealed {
+            object OOO : Sealed()
+        }
+
+        typealias OOO = Sealed.OOO
+    }
+
+    private class Derived : Base() {
+
+        fun foo(): Sealed {
+            ArrayList<Int>()
+            return OOO
+        }
+
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/imports/OptimizeImportsTestGenerated.java

@@ -155,6 +155,12 @@ public class OptimizeImportsTestGenerated extends AbstractOptimizeImportsTest {
         doTest(fileName);
     }
 
+    @TestMetadata("KT13766.kt")
+    public void testKT13766() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/editor/optimizeImports/KT13766.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("KT9875.kt")
     public void testKT9875() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/editor/optimizeImports/KT9875.kt");