Allow modifier 'inner' on a class nested in enum entry class

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/KeywordCompletion.kt

@@ -388,11 +388,7 @@ object KeywordCompletion {
                         else -> return true
                     }
 
-                    val modifierParents = ModifierCheckerCore.possibleParentTargetMap[keywordTokenType]
-                    if (modifierParents != null && parentTarget !in modifierParents) return false
-
-                    val deprecatedParents = ModifierCheckerCore.deprecatedParentTargetMap[keywordTokenType]
-                    if (deprecatedParents != null && parentTarget in deprecatedParents) return false
+                    if (!ModifierCheckerCore.isPossibleParentTarget(keywordTokenType, parentTarget, languageVersionSettings)) return false
 
                     return true
                 }
@@ -451,6 +447,17 @@ object KeywordCompletion {
         }
     }
 
+    private fun isModifierParentSupportedAtLanguageLevel(
+            keyword: KtKeywordToken,
+            target: KotlinTarget,
+            languageVersionSettings: LanguageVersionSettings
+    ): Boolean {
+        if (keyword == KtTokens.INNER_KEYWORD && target == ENUM_ENTRY) {
+            return languageVersionSettings.supportsFeature(LanguageFeature.InnerClassInEnumEntryClass)
+        }
+        return true
+    }
+
     // builds text within scope (or from the start of the file) before position element excluding almost all declarations
     private fun buildReducedContextBefore(builder: StringBuilder, position: PsiElement, scope: PsiElement?) {
         if (position == scope) return