MutableMap.iterator() returns MutableIterator.

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

@@ -190,6 +190,14 @@ public inline fun <K, V> MutableMap<K, V>.getOrPut(key: K, defaultValue: () -> V
  */
 public operator fun <K, V> Map<K, V>.iterator(): Iterator<Map.Entry<K, V>> = entries.iterator()
 
+/**
+ * Returns a [MutableIterator] over the mutable entries in the [MutableMap].
+ *
+ */
+@JvmVersion
+@JvmName("mutableIterator")
+public operator fun <K, V> MutableMap<K, V>.iterator(): MutableIterator<MutableMap.MutableEntry<K, V>> = entries.iterator()
+
 /**
  * Populates the given `destination` [Map] with entries having the keys of this map and the values obtained
  * by applying the `transform` function to each entry in this [Map].

libraries/stdlib/test/collections/MapJVMTest.kt

@@ -41,6 +41,17 @@ class MapJVMTest {
         assertEquals("B", prop.getProperty("b", "fail"))
     }
 
+    @test fun iterateAndRemove() {
+        val map = (1..5).toMap({ it }, { 'a' + it }).toLinkedMap()
+        val iterator = map.iterator()
+        while (iterator.hasNext()) {
+            if (iterator.next().key % 2 == 0)
+                iterator.remove()
+        }
+        assertEquals(listOf(1, 3, 5), map.keys.toList())
+        assertEquals(listOf('b', 'd', 'f'), map.values.toList())
+    }
+
     @test fun getOrPutFailsOnConcurrentMap() {
         val map = ConcurrentHashMap<String, Int>()