Add EnumSet.

Add EnumSet.

BUG=
R=sigurdm@google.com

Committed: https://github.com/dart-lang/sdk/commit/2ddf46bb8569354814bdd55ab2b098be661bfa66

[Johnni Winther, 2016-01-08 14:40:35]

johnniwinther@google.com changed reviewers:
+ sigurdm@google.com

[sigurdm, 2016-01-11 08:48:55]

LGTM

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/univer...
File pkg/compiler/lib/src/universe/class_set.dart (right):

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/univer...
pkg/compiler/lib/src/universe/class_set.dart:420: /// The [mask] defines the
included subset of the subtypes based on their
It is not clear from the description of `mask` that we accept all subtypes with
an *intersecting* mask.

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/util/e...
File pkg/compiler/lib/src/util/enumset.dart (right):

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/util/e...
pkg/compiler/lib/src/util/enumset.dart:74: if (other is! EnumSet) return false;
Ideally this should be
```
if (other is! EnumSet<E>) return false;
```
I don't know about the performance implications of that though...

[Johnni Winther, 2016-01-11 10:29:51]

Description was changed from

==========
Add EnumSet.

BUG=
==========

to

==========
Add EnumSet.

BUG=
R=sigurdm@google.com

Committed:
https://github.com/dart-lang/sdk/commit/2ddf46bb8569354814bdd55ab2b098be661bfa66
==========

[Johnni Winther, 2016-01-11 10:29:53]

Committed patchset #2 (id:20001) manually as
2ddf46bb8569354814bdd55ab2b098be661bfa66 (presubmit successful).

[Johnni Winther, 2016-01-22 11:54:13]

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/univer...
File pkg/compiler/lib/src/universe/class_set.dart (right):

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/univer...
pkg/compiler/lib/src/universe/class_set.dart:420: /// The [mask] defines the
included subset of the subtypes based on their
On 2016/01/11 08:48:55, sigurdm wrote:
> It is not clear from the description of `mask` that we accept all subtypes
with
> an *intersecting* mask.

Updated the comments.

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/util/e...
File pkg/compiler/lib/src/util/enumset.dart (right):

https://codereview.chromium.org/1568213003/diff/1/pkg/compiler/lib/src/util/e...
pkg/compiler/lib/src/util/enumset.dart:74: if (other is! EnumSet) return false;
On 2016/01/11 08:48:55, sigurdm wrote:
> Ideally this should be
> ```
> if (other is! EnumSet<E>) return false;
> ```
> I don't know about the performance implications of that though...

Updated. Should be OK as the VM canonicalizes the instantiated types.