addRemoveModifier: shouldn't add extra new line

#KT-26635 Fixed

compiler/psi/src/org/jetbrains/kotlin/psi/addRemoveModifier.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
 package org.jetbrains.kotlin.psi.addRemoveModifier
@@ -22,7 +11,6 @@ import com.intellij.psi.PsiWhiteSpace
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens.*
 import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.psi.psiUtil.getNextSiblingIgnoringWhitespace
 import org.jetbrains.kotlin.psi.psiUtil.siblings
 
 private fun KtModifierListOwner.addModifierList(newModifierList: KtModifierList): KtModifierList {
@@ -98,7 +86,7 @@ internal fun addModifier(modifierList: KtModifierList, modifier: KtModifierKeywo
         val lastChild = modifierList.lastChild
         val anchor = lastChild?.siblings(forward = false)?.firstOrNull(::placeAfter).let {
             when {
-                it?.nextSibling is PsiWhiteSpace && (it is KtAnnotation || it is KtAnnotationEntry) -> it.nextSibling
+                it?.nextSibling is PsiWhiteSpace && (it is KtAnnotation || it is KtAnnotationEntry || it is PsiComment) -> it.nextSibling
                 it == null && modifierList.firstChild is PsiWhiteSpace -> modifierList.firstChild
                 else -> it
             }

idea/testData/multiModuleQuickFix/createActual/annotationWithComment/common/a.kt

@@ -0,0 +1,6 @@
+// "Create actual annotation class for module testModule_JVM (JVM)" "true"
+
+@RegAnn // some comment
+expect annotation class SomeAnn<caret>
+
+annotation class RegAnn

idea/testData/multiModuleQuickFix/createActual/annotationWithComment/jvm/SomeAnn.kt.after

@@ -0,0 +1,2 @@
+@RegAnn // some comment
+actual annotation class SomeAnn

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixMultiModuleTestGenerated.java

@@ -159,6 +159,11 @@ public class QuickFixMultiModuleTestGenerated extends AbstractQuickFixMultiModul
             runTest("idea/testData/multiModuleQuickFix/createActual/annotationOptionalExpectationNoDir/");
         }
 
+        @TestMetadata("annotationWithComment")
+        public void testAnnotationWithComment() throws Exception {
+            runTest("idea/testData/multiModuleQuickFix/createActual/annotationWithComment/");
+        }
+
         @TestMetadata("class")
         public void testClass() throws Exception {
             runTest("idea/testData/multiModuleQuickFix/createActual/class/");