dart2js cps: Bugfix in FlatTypeMask.isDisjoint.

dart2js cps: Bugfix in FlatTypeMask.isDisjoint.

The predicate would answer incorrectly when asked if subclasses of A
is disjoint from subtypes of B, where B is a subtype of A.

Example from the compiler:

  abstract class _MinifiedFieldNamer implements Namer

  class MinifyNamer extends Namer with _MinifiedFieldNamer

[subclass=Namer] vs [subtype=_MinifiedFieldNamer] were found to be
disjoint, even though the MinifyNamer class exists.

BUG=
R=kmillikin@google.com

Committed: https://github.com/dart-lang/sdk/commit/28ce0ee8acd3b0a6fc210449f2f496aa9b24f95c

[asgerf, 2016-01-26 13:30:43]

asgerf@google.com changed reviewers:
+ sigmund@google.com

[asgerf, 2016-01-26 13:41:29]

asgerf@google.com changed reviewers:
+ kmillikin@google.com
- sigmund@google.com

[asgerf, 2016-01-26 13:41:29]

R=kmillikin since Siggi is OOO.

BTW this fixes dummy_compiler_test and friends.

[Kevin Millikin (Google), 2016-01-26 14:04:36]

lgtm

[asgerf, 2016-01-26 14:41:57]

Description was changed from

==========
dart2js cps: Bugfix in FlatTypeMask.isDisjoint.

The predicate would answer incorrectly when asked if subclasses of A
is disjoint from subtypes of B, where B is a subtype of A.

Example from the compiler:

  abstract class _MinifiedFieldNamer implements Namer

  class MinifyNamer extends Namer with _MinifiedFieldNamer

[subclass=Namer] vs [subtype=_MinifiedFieldNamer] were found to be
disjoint, even though the MinifyNamer class exists.

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

to

==========
dart2js cps: Bugfix in FlatTypeMask.isDisjoint.

The predicate would answer incorrectly when asked if subclasses of A
is disjoint from subtypes of B, where B is a subtype of A.

Example from the compiler:

  abstract class _MinifiedFieldNamer implements Namer

  class MinifyNamer extends Namer with _MinifiedFieldNamer

[subclass=Namer] vs [subtype=_MinifiedFieldNamer] were found to be
disjoint, even though the MinifyNamer class exists.

BUG=
R=kmillikin@google.com

Committed:
https://github.com/dart-lang/sdk/commit/28ce0ee8acd3b0a6fc210449f2f496aa9b24f95c
==========

[asgerf, 2016-01-26 14:41:58]

Committed patchset #1 (id:1) manually as
28ce0ee8acd3b0a6fc210449f2f496aa9b24f95c (presubmit successful).

[Siggi Cherem (dart-lang), 2016-02-04 22:31:34]

sigmund@google.com changed reviewers:
+ sigmund@google.com

[Siggi Cherem (dart-lang), 2016-02-04 22:31:34]

lgtm

Thanks for the fix! Let's add a unittest to
tests/compiler/dart2js/type_mask_disjoint_test to cover this.