Revert "[es6] Optimize String{Starts, Ends}With"

Revert "[es6] Optimize String{Starts, Ends}With"

This reverts commit b7db5cd9c761de2f15112ce4d46c7ade8c749ac0
(https://codereview.chromium.org/1324353002/).

Our internal dashboard shows that this patch has introduced massive (3x) performance regressions for string ops. This is probably due to it repeatedly invoking %_StringCharCodeAt in a loop, which is far from cheap (has to dispatch on one of our 30+ string representations each time).

TBR=dehrenberg@chromium.org
BUG=

Committed: https://crrev.com/84b4e1d4336454908a6824e81d5fa5257003eaf0
Cr-Commit-Position: refs/heads/master@{#31981}

[rossberg, 2015-11-13 12:40:30]

Description was changed from

==========
Revert "[es6] Optimize String{Starts, Ends}With"

This reverts commit b7db5cd9c761de2f15112ce4d46c7ade8c749ac0
(https://codereview.chromium.org/1324353002/).

Our internal dashboard shows that this patch has introduced massive (3x)
performance regressions for string ops. This is probably due to it repeatedly
invoking %_StringCharCodeAt in a loop, which is far from cheap (has to dispatch
on one of our 30+ string representations each time).

R=dehrenberg@chromium.org
BUG=
==========

to

==========
Revert "[es6] Optimize String{Starts, Ends}With"

This reverts commit b7db5cd9c761de2f15112ce4d46c7ade8c749ac0
(https://codereview.chromium.org/1324353002/).

Our internal dashboard shows that this patch has introduced massive (3x)
performance regressions for string ops. This is probably due to it repeatedly
invoking %_StringCharCodeAt in a loop, which is far from cheap (has to dispatch
on one of our 30+ string representations each time).

TBR=dehrenberg@chromium.org
BUG=
==========

[rossberg, 2015-11-13 12:40:55]

The CQ bit was checked by rossberg@chromium.org

[commit-bot: I haz the power, 2015-11-13 12:41:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1439083003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1439083003/1

[commit-bot: I haz the power, 2015-11-13 13:17:37]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-14 23:21:27]

Patchset 1 (id:??) landed as
https://crrev.com/84b4e1d4336454908a6824e81d5fa5257003eaf0
Cr-Commit-Position: refs/heads/master@{#31981}