stdlib: Uncomment extensions with reified parameters

runtime/src/main/kotlin/kotlin/collections/Collections.kt

@@ -952,8 +952,6 @@ public inline fun <T, C : MutableCollection<in T>> Iterable<T>.filterIndexedTo(d
 /**
  * Returns a list containing all elements that are instances of specified type parameter R.
  */
-/*
-@FixmeReified
 public inline fun <reified R> Iterable<*>.filterIsInstance(): List<@kotlin.internal.NoInfer R> {
     return filterIsInstanceTo(ArrayList<R>())
 }
@@ -965,7 +963,7 @@ public inline fun <reified R, C : MutableCollection<in R>> Iterable<*>.filterIsI
     for (element in this) if (element is R) destination.add(element)
     return destination
 }
-*/
+
 
 /**
  * Returns a list containing all elements not matching the given [predicate].

runtime/src/main/kotlin/kotlin/sequences/Sequences.kt

@@ -941,22 +941,18 @@ public inline fun <T, C : MutableCollection<in T>> Sequence<T>.filterIndexedTo(d
 /**
  * Returns a sequence containing all elements that are instances of specified type parameter R.
  */
-@FixmeReified
 public inline fun <reified R> Sequence<*>.filterIsInstance(): Sequence<@kotlin.internal.NoInfer R> {
-    //@Suppress("UNCHECKED_CAST")
-    //return filter { it is R } as Sequence<R>
-    TODO()
+    @Suppress("UNCHECKED_CAST")
+    return filter { it is R } as Sequence<R>
 }
 
 /**
  * Appends all elements that are instances of specified type parameter R to the given [destination].
  */
-@FixmeReified
 @Suppress("UNUSED_PARAMETER")
 public inline fun <reified R, C : MutableCollection<in R>> Sequence<*>.filterIsInstanceTo(destination: C): C {
-    //for (element in this) if (element is R) destination.add(element)
-    //return destination
-    TODO()
+    for (element in this) if (element is R) destination.add(element)
+    return destination
 }
 
 /**