Formatter: fix line break between declarations with comment

#KT-12490 Fixed
#KT-35088 Fixed

idea/testData/multiModuleQuickFix/createExpect/commented/header/My.kt.after

@@ -6,6 +6,7 @@
 expect class My {
     fun foo(param: String): Int
     fun String.bar(y: Double): Boolean
+
     /**
      * Dokka comment: Just does nothing
      */

idea/testData/multiModuleQuickFix/createExpect/sealedClass/header/My.kt.after

@@ -7,9 +7,11 @@ expect sealed class My(x: Double) {
     object First : My {
         override val num: Int
     }
+
     class Some(num: Int) : My {
         override val num: Int
     }
+
     object Best : My {
         override val num: Int
         override fun isGood(): Boolean