Loading descriptors from incremental cache instead of package classes.

compiler/util/src/org/jetbrains/jet/utils/addToStdlib.kt

@@ -17,6 +17,7 @@
 package org.jetbrains.jet.utils.addToStdlib
 
 import java.util.HashMap
+import java.util.Collections
 
 fun <K, V> Map<K, V>.filterKeys(predicate: (K)->Boolean): Map<K, V> {
     val result = HashMap<K, V>()
@@ -27,3 +28,7 @@ fun <K, V> Map<K, V>.filterKeys(predicate: (K)->Boolean): Map<K, V> {
     }
     return result
 }
+
+fun <T: Any> T?.singletonOrEmptyList(): List<T> = if (this != null) Collections.singletonList(this) else Collections.emptyList()
+
+fun <T: Any> T?.singletonOrEmptySet(): Set<T> = if (this != null) Collections.singleton(this) else Collections.emptySet()

compiler/util/src/org/jetbrains/jet/utils/intellijUtil.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2014 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.jet.utils.intellij
+
+import com.intellij.openapi.util.Pair
+
+public fun <A> Pair<A, *>.component1(): A = getFirst()
+
+public fun <B> Pair<*, B>.component2(): B = getSecond()