Remove dependency of serialization on frontend

Move ApplicationExtensionDescriptor and ProjectExtensionDescriptor to
:compiler:util.

compiler/serialization/build.gradle.kts

@@ -5,8 +5,8 @@ plugins {
 
 dependencies {
     compile(project(":compiler:resolution"))
-    compile(project(":compiler:frontend"))
     compile(project(":core:deserialization"))
+    api(project(":compiler:util"))
 
     compileOnly(intellijCoreDep()) { includeJars("intellij-core", rootProject = rootProject) }
 }

compiler/util/src/org/jetbrains/kotlin/extensions/ApplicationExtensionDescriptor.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2018 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2021 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.
  */
 

compiler/util/src/org/jetbrains/kotlin/extensions/ProjectExtensionDescriptor.kt

@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2015 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 2010-2021 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.extensions