Handle named mixin application in emitter

Handle named mixin application in emitter

Fixes regression in language/regress_18713_test with --csp

Closes #29844
Closes #29843

This reapplies Johnni's change from here: https://codereview.chromium.org/2934783002/

I am submitting it instead of Johnni because without this change we are blocking the new dart update internally in Google.
BUG=
TBR

Committed: https://github.com/dart-lang/sdk/commit/0753ac689eb3c89bbf8ee88e76e9dda23b59451d

[Emily Fortuna, 2017-06-13 21:22:26]

Description was changed from

==========
Handle named mixin application in emitter

Fixes regression in language/regress_18713_test with --csp

Closes #29844
Closes #29843


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

to

==========
Handle named mixin application in emitter

Fixes regression in language/regress_18713_test with --csp

Closes #29844
Closes #29843

This reapplies Johnni's change from here:
https://codereview.chromium.org/2934783002/

I am submitting it instead of Johnni because without this change we are blocking
the new dart update internally in Google.
BUG=
TBR
==========

[Emily Fortuna, 2017-06-13 21:22:27]

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

[Emily Fortuna, 2017-06-13 21:23:24]

Description was changed from

==========
Handle named mixin application in emitter

Fixes regression in language/regress_18713_test with --csp

Closes #29844
Closes #29843

This reapplies Johnni's change from here:
https://codereview.chromium.org/2934783002/

I am submitting it instead of Johnni because without this change we are blocking
the new dart update internally in Google.
BUG=
TBR
==========

to

==========
Handle named mixin application in emitter

Fixes regression in language/regress_18713_test with --csp

Closes #29844
Closes #29843

This reapplies Johnni's change from here:
https://codereview.chromium.org/2934783002/

I am submitting it instead of Johnni because without this change we are blocking
the new dart update internally in Google.
BUG=
TBR

Committed:
https://github.com/dart-lang/sdk/commit/0753ac689eb3c89bbf8ee88e76e9dda23b59451d
==========

[Emily Fortuna, 2017-06-13 21:23:25]

Committed patchset #1 (id:1) manually as
0753ac689eb3c89bbf8ee88e76e9dda23b59451d (presubmit successful).

[Johnni Winther, 2017-06-14 07:46:05]

lgtm