Fixed caret position for KT-5906 Smart completion of anonymous object should preselect single method body

#KT-5906 Fixed

idea/testData/completion/handlers/smart/AnonymousObject3.kt.after

@@ -1,6 +1,6 @@
 var r : Runnable = object: Runnable {
     override fun run() {
-        throw UnsupportedOperationException()
+        <caret><selection>throw UnsupportedOperationException()</selection>
     }
 }