Optimize PluginDeclarationProviderFactory.getStubBasedPackageMemberDeclarationProvider

Add cache for fast package exists check in specific module
 #KT-16850 fixed

idea/idea-core/src/org/jetbrains/kotlin/idea/core/util/CachedValueHelpers.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010-2017 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.idea.core.util
+
+import com.intellij.openapi.project.Project
+import com.intellij.psi.util.CachedValue
+import com.intellij.psi.util.CachedValueProvider
+import com.intellij.psi.util.CachedValuesManager
+import kotlin.reflect.KProperty
+
+operator fun <T> CachedValue<T>.getValue(o: Any, property: KProperty<*>): T = value
+
+fun <T> CachedValue(project: Project, trackValue: Boolean = false, provider: () -> CachedValueProvider.Result<T>) =
+        CachedValuesManager.getManager(project).createCachedValue(provider, trackValue)