Provide mutableSetOf and mutableMapOf

#KT-9663 Fixed

libraries/stdlib/src/kotlin/collections/Maps.kt

@@ -46,6 +46,14 @@ public fun <K, V> mapOf(): Map<K, V> = emptyMap()
 @JvmVersion
 public fun <K, V> mapOf(pair: Pair<K, V>): Map<K, V> = Collections.singletonMap(pair.first, pair.second)
 
+/**
+ * Returns a new [MutableMap] with the specified contents, given as a list of pairs
+ * where the first component is the key and the second is the value.
+ * This map preserves insertion order so iterating through the map's entries will be in the same order.
+ */
+public fun <K, V> mutableMapOf(vararg pairs: Pair<K, V>): MutableMap<K, V>
+        = LinkedHashMap<K, V>(mapCapacity(pairs.size)).apply { putAll(pairs) }
+
 /**
  * Returns a new [HashMap] with the specified contents, given as a list of pairs
  * where the first component is the key and the second is the value.

libraries/stdlib/src/kotlin/collections/Sets.kt

@@ -31,6 +31,8 @@ public fun <T> setOf(vararg elements: T): Set<T> = if (elements.size > 0) elemen
 /** Returns an empty read-only set.  The returned set is serializable (JVM). */
 public fun <T> setOf(): Set<T> = emptySet()
 
+/** Returns a new [MutableSet] with the given elements. */
+public fun <T> mutableSetOf(vararg elements: T): MutableSet<T> = elements.toCollection(LinkedHashSet(mapCapacity(elements.size)))
 
 /** Returns a new [HashSet] with the given elements. */
 public fun <T> hashSetOf(vararg elements: T): HashSet<T> = elements.toCollection(HashSet(mapCapacity(elements.size)))