Remove code optimizing for TypedArrays being @@isConcatSpreadable

Remove code optimizing for TypedArrays being @@isConcatSpreadable

In theory, a user could define the Symbol.isConcatSpreadable property
somewhere in the TypedArray class hierarchy. Array.prototype.concat
optimizes for this case and has templated code for fast concat over
TypedArrays. However, the default environment doesn't have this
property set (it would probably not be web-compatible) and there isn't
clear demand for this optimization. This patch removes that
special-case code.

R=adamk

Committed: https://crrev.com/a686f4f97c02056b984aff5312b57d9a9bf8d050
Cr-Commit-Position: refs/heads/master@{#34195}

[Dan Ehrenberg, 2016-02-20 01:30:07]

The CQ bit was checked by littledan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-02-20 01:30:08]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1720533003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1720533003/1

[Dan Ehrenberg, 2016-02-20 01:33:18]

The CQ bit was checked by littledan@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-02-20 01:33:25]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1720533003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1720533003/20001

[Dan Ehrenberg, 2016-02-20 01:50:49]

littledan@chromium.org changed reviewers:
+ cbruni@chromium.org

[commit-bot: I haz the power, 2016-02-20 01:52:52]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-02-20 01:52:53]

Dry run: This issue passed the CQ dry run.

[adamk, 2016-02-20 02:39:32]

This seems fine to me, but I'll defer to cbruni, mostly because I'm curious how
this code ended up here in the first place. It looks like it was moved over from
elements.cc, and I wonder if it was there simply for "completeness". This was
long before @@isConcatSpreadable existed, so that's surely not the reason this
code existed.

https://codereview.chromium.org/1720533003/diff/20001/src/builtins.cc
File src/builtins.cc (right):

https://codereview.chromium.org/1720533003/diff/20001/src/builtins.cc#newcode...
src/builtins.cc:1182: // |array| is guaranteed to be an array or typed array.
This comment is now out of date.

[Camillo Bruni, 2016-02-22 10:13:01]

On 2016/02/20 at 02:39:32, adamk wrote:
> This seems fine to me, but I'll defer to cbruni, mostly because I'm curious
how this code ended up here in the first place. It looks like it was moved over
from elements.cc, and I wonder if it was there simply for "completeness". This
was long before @@isConcatSpreadable existed, so that's surely not the reason
this code existed.


Yeah I moved the code during my elements.cc/array builtins cleanup
(https://codereview.chromium.org/1330483003) and it was orignially in
runtime-array.cc.
Probably elements.cc or even a seeparate file would be a better place for this
monstrosity ;).

[Camillo Bruni, 2016-02-22 10:15:07]

lgtm

[Dan Ehrenberg, 2016-02-22 18:39:16]

The CQ bit was checked by littledan@chromium.org

[commit-bot: I haz the power, 2016-02-22 18:39:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1720533003/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1720533003/20001

[commit-bot: I haz the power, 2016-02-22 18:58:34]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-02-22 18:59:24]

Description was changed from

==========
Remove code optimizing for TypedArrays being @@isConcatSpreadable

In theory, a user could define the Symbol.isConcatSpreadable property
somewhere in the TypedArray class hierarchy. Array.prototype.concat
optimizes for this case and has templated code for fast concat over
TypedArrays. However, the default environment doesn't have this
property set (it would probably not be web-compatible) and there isn't
clear demand for this optimization. This patch removes that
special-case code.

R=adamk
==========

to

==========
Remove code optimizing for TypedArrays being @@isConcatSpreadable

In theory, a user could define the Symbol.isConcatSpreadable property
somewhere in the TypedArray class hierarchy. Array.prototype.concat
optimizes for this case and has templated code for fast concat over
TypedArrays. However, the default environment doesn't have this
property set (it would probably not be web-compatible) and there isn't
clear demand for this optimization. This patch removes that
special-case code.

R=adamk

Committed: https://crrev.com/a686f4f97c02056b984aff5312b57d9a9bf8d050
Cr-Commit-Position: refs/heads/master@{#34195}
==========

[commit-bot: I haz the power, 2016-02-22 18:59:25]

Patchset 2 (id:??) landed as
https://crrev.com/a686f4f97c02056b984aff5312b57d9a9bf8d050
Cr-Commit-Position: refs/heads/master@{#34195}