move PackagePartClassUtils to frontend.common-psi

^KT-53097

compiler/frontend.common-psi/src/org/jetbrains/kotlin/load/kotlin/PackagePartClassUtils.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 2010-2022 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.load.kotlin
@@ -24,7 +13,6 @@ import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.name.NameUtils
 import org.jetbrains.kotlin.psi.KtFile
-import java.util.*
 
 object PackagePartClassUtils {
     @JvmStatic fun getPathHashCode(file: VirtualFile): Int =
@@ -62,4 +50,4 @@ object PackagePartClassUtils {
         if (baseName == "_") return null
         return "${decapitalizeAsJavaClassName(baseName)}.${KotlinFileType.EXTENSION}"
     }
-}
+}