Provide mutableSetOf and mutableMapOf

#KT-9663 Fixed

libraries/stdlib/test/collections/MapTest.kt

@@ -209,6 +209,12 @@ class MapTest {
         assertEquals(2, map["b"])
     }
 
+    @test fun createMutableMap() {
+        val map = mutableMapOf("b" to 1, "c" to 2)
+        map.put("a", 3)
+        assertEquals(listOf("b" to 1, "c" to 2, "a" to 3), map.toList())
+    }
+
     @test fun createLinkedMap() {
         val map = linkedMapOf(Pair("c", 3), Pair("b", 2), Pair("a", 1))
         assertEquals(1, map["a"])

libraries/stdlib/test/collections/SetOperationsTest.kt

@@ -56,7 +56,7 @@ class SetOperationsTest {
         assertEquals(setOf("a", "foo", "beer", "cheese", "bar"), set)
         assertTrue(set !== setOriginal)
 
-        val mset = hashSetOf("a")
+        val mset = mutableSetOf("a")
         mset += "foo"
         mset += listOf("beer", "a")
         mset += arrayOf("cheese", "beer")