Breaking change. Map operations revisited.

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

@@ -19,7 +19,8 @@ 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> {
+deprecated("Replace with filterKeys when bootstrapped")
+fun <K, V> Map<K, V>.filterKeys_tmp(predicate: (K)->Boolean): Map<K, V> {
     val result = HashMap<K, V>()
     for ((k, v) in this) {
         if (predicate(k)) {