Change List/Set/Map/Queue.from constructrs to accept any iterable.

sdk/lib/core/iterable.dart

Index: sdk/lib/core/iterable.dart
diff --git a/sdk/lib/core/iterable.dart b/sdk/lib/core/iterable.dart
index 7f2c5d6ec93331b2bff02df5ce815d5d64e13611..d4f482b7ef2b3a23016e9fb5f3d943b6a6244c28 100644
--- a/sdk/lib/core/iterable.dart
+++ b/sdk/lib/core/iterable.dart
@@ -56,6 +56,9 @@ abstract class Iterable<E> {
   /**
    * Returns a new `Iterator` that allows iterating the elements of this
    * `Iterable`.
+   *
+   * Modifying the underlying data after creating the new iterator
+   * may cause an error the next time [Iterator.moveNext] is called.
    */
   Iterator<E> get iterator;