Remove kIsPossibleArrowFormals option from ParseAssignmentExpression

Remove kIsPossibleArrowFormals option from ParseAssignmentExpression

The path used by that option only comes into play when default parameters
are allowed but destructuring assignment is disallowed. Removing it
allows the removal of one implementation of ParseExpression, and makes
it clearer which code will be dead once all the destructuring flags
are removed.

Also made the |flags| param strongly typed instead of an int.

Committed: https://crrev.com/b8a4aeaee04120fa8d560b1e30083277cc6a34eb
Cr-Commit-Position: refs/heads/master@{#33918}

[adamk, 2016-02-11 01:19:54]

adamk@chromium.org changed reviewers:
+ rossberg@chromium.org

[adamk, 2016-02-11 01:19:54]

This depends on https://codereview.chromium.org/1688833004 landing first

[rossberg, 2016-02-11 11:55:58]

lgtm

[adamk, 2016-02-11 19:08:57]

The CQ bit was checked by adamk@chromium.org

[commit-bot: I haz the power, 2016-02-11 19:09:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1691653002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1691653002/1

[commit-bot: I haz the power, 2016-02-11 19:10:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-11 19:11:02]

Description was changed from

==========
Remove kIsPossibleArrowFormals option from ParseAssignmentExpression

The path used by that option only comes into play when default parameters
are allowed but destructuring assignment is disallowed. Removing it
allows the removal of one implementation of ParseExpression, and makes
it clearer which code will be dead once all the destructuring flags
are removed.

Also made the |flags| param strongly typed instead of an int.
==========

to

==========
Remove kIsPossibleArrowFormals option from ParseAssignmentExpression

The path used by that option only comes into play when default parameters
are allowed but destructuring assignment is disallowed. Removing it
allows the removal of one implementation of ParseExpression, and makes
it clearer which code will be dead once all the destructuring flags
are removed.

Also made the |flags| param strongly typed instead of an int.

Committed: https://crrev.com/b8a4aeaee04120fa8d560b1e30083277cc6a34eb
Cr-Commit-Position: refs/heads/master@{#33918}
==========

[commit-bot: I haz the power, 2016-02-11 19:11:03]

Patchset 1 (id:??) landed as
https://crrev.com/b8a4aeaee04120fa8d560b1e30083277cc6a34eb
Cr-Commit-Position: refs/heads/master@{#33918}