forEach will be passed functions of type `(int) -> int`, so its
signature needs to accept them; previously its signature only accepted
`(dynamic) -> int` (a more specific type).
Change-Id: Ibe7116f05d3c9d73f01c090836a9b11bb7dcf597
Reviewed-on: https://dart-review.googlesource.com/19221
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Commit-Queue: Paul Berry <paulberry@google.com>