Add Timer implementation for dart2js. Also moves tests to appropriate location.

tests/isolate/isolate.status

Index: tests/isolate/isolate.status
diff --git a/tests/isolate/isolate.status b/tests/isolate/isolate.status
index f527064a1f645da5f8cc9a3df1a783744582abd2..84608111a306deb4cde4147fbf84f4be4f2ac4e9 100644
--- a/tests/isolate/isolate.status
+++ b/tests/isolate/isolate.status
@@ -81,6 +81,12 @@ spawn_uri_test: Skip # loading another file is not supported in d8
 spawn_uri_negative_test: Skip # ditto
 spawn_uri_vm_test: Skip # test uses a ".dart" suffix that only works in vm.
 spawn_uri_vm_negative_test: Skip # ditto above.
+timer_cancel_test: Fail # Needs Timer to run.

[kasperl, 2012/08/09 06:15:33]

Fail, OK -- it is not something we're looking to address. Alternatively, we
should try to make it possible to determine (at runtime) whether or not there is
timer support on the platform (maybe new Timer can throw if not?) and rewrite
the tests to check for that. When running on raw d8, I'd really like this to
fail in a predictable (and tested) way.

[Siggi Cherem (dart-lang), 2012/08/09 20:37:15]

actually, that's what happens today already. I added a test for it
(timer_not_available_test), marked all these as Fail, OK.

I wonder if we should just mark them as Skip though - it doesn't seem that we
are gaining any information from running these.

+timer_cancel1_test: Fail # Needs Timer to run.
+timer_cancel2_test: Fail # Needs Timer to run.
+multiple_timer_test: Fail # Needs Timer to run.
+timer_test: Fail # Needs Timer to run.
+timer_repeat_test: Fail # Needs Timer to run.
 
 [ $compiler == dart2js && $runtime == none ]
 *: Fail, Pass # TODO(ahe): Triage these tests.