Misc: Render MemberInfo as 'abstract' only if it's present in source

#KT-26533 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/memberInfo/KotlinMemberInfo.kt

@@ -32,6 +32,7 @@ import org.jetbrains.kotlin.descriptors.MemberDescriptor
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.idea.refactoring.isInterfaceClass
 import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
+import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.renderer.DescriptorRendererModifier
 import org.jetbrains.kotlin.utils.addToStdlib.firstIsInstanceOrNull
@@ -63,7 +64,7 @@ class KotlinMemberInfo @JvmOverloads constructor(
         }
         else {
             displayName = RENDERER.render(memberDescriptor)
-            if (memberDescriptor is MemberDescriptor && memberDescriptor.modality == Modality.ABSTRACT) {
+            if (member.hasModifier(KtTokens.ABSTRACT_KEYWORD)) {
                 displayName = "abstract $displayName"
             }
             if (isCompanionMember) {