Refactoring: delete unused CachedValueProperty class

compiler/util/src/org/jetbrains/kotlin/utils/CachedValueProperty.kt

@@ -1,36 +0,0 @@
-/*
- * 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.
- */
-
-package org.jetbrains.kotlin.utils
-
-import kotlin.reflect.KProperty
-
-class CachedValueProperty<out TValue : Any, TTimestamp : Any>(
-        private val calculator: () -> TValue,
-        private val timestampCalculator: () -> TTimestamp
-) {
-    private var value: TValue? = null
-    private var timestamp: TTimestamp? = null
-
-    operator fun getValue(thisRef: Any?, property: KProperty<*>): TValue {
-        val currentTimestamp = timestampCalculator()
-        if (value == null || timestamp != currentTimestamp) {
-            value = calculator()
-            timestamp = currentTimestamp
-        }
-        return value!!
-    }
-}