Introduce toMap with key-value pair selector.

#KT-6657

libraries/stdlib/src/generated/_Collections.kt

@@ -1082,6 +1082,20 @@ public inline fun <T, K, V> Iterable<T>.toMap(selector: (T) -> K, transform: (T)
     return result
 }
 
+/**
+ * Returns a [Map] containing key-value pairs provided by [transform] function applied to elements of the given collection.
+ * If any of two pairs would have the same key the last one gets added to the map.
+ */
+@kotlin.jvm.JvmName("toMapOfPairs")
+public inline fun <T, K, V> Iterable<T>.toMap(transform: (T) -> Pair<K, V>): Map<K, V> {
+    val capacity = (collectionSizeOrDefault(10)/.75f) + 1
+    val result = LinkedHashMap<K, V>(Math.max(capacity.toInt(), 16))
+    for (element in this) {
+        result += transform(element)
+    }
+    return result
+}
+
 /**
  * Returns a [Map] containing the elements from the given collection indexed by the key
  * returned from [selector] function applied to each element.