Quick Fixes: Implement "Rename unresolved reference" fix

#KT-8795 Fixed

core/util.runtime/src/org/jetbrains/kotlin/utils/HammingComparator.kt

@@ -0,0 +1,29 @@
+/*
+ * 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 java.util.*
+
+class HammingComparator<T>(private val referenceString: String, private val asString: T.() -> String) : Comparator<T> {
+    private fun countDifference(s1: String): Int {
+        return (0..Math.min(s1.lastIndex, referenceString.lastIndex)).count { s1[it] != referenceString[it] }
+    }
+
+    override fun compare(lookupItem1: T, lookupItem2: T): Int {
+        return countDifference(lookupItem1.asString()) - countDifference(lookupItem2.asString())
+    }
+}

core/util.runtime/src/org/jetbrains/kotlin/utils/collections.kt

@@ -85,6 +85,8 @@ public fun <K> Iterable<K>.mapToIndex(): Map<K, Int> {
 
 public inline fun <T, C: Collection<T>> C.ifEmpty(body: () -> C): C = if (isEmpty()) body() else this
 
+public inline fun <T> Array<out T>.ifEmpty(body: () -> Array<out T>): Array<out T> = if (isEmpty()) body() else this
+
 public fun <T: Any> emptyOrSingletonList(item: T?): List<T> = if (item == null) listOf() else listOf(item)
 
 public fun <T: Any> MutableCollection<T>.addIfNotNull(t: T?) {