[strong] make function and class declarations lexical & immutable

[strong] make function and class declarations lexical & immutable

R=arv@chromium.org
BUG=

Committed: https://crrev.com/7b49ed658cec317ad8009b08812f8aa42abebb71
Cr-Commit-Position: refs/heads/master@{#26755}

[arv (Not doing code reviews), 2015-02-19 15:48:56]

LGTM

Nice. A lot simpler than I would have thought.

[rossberg, 2015-02-19 15:50:46]

The CQ bit was checked by rossberg@chromium.org

[commit-bot: I haz the power, 2015-02-19 15:51:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/932283003/1

[commit-bot: I haz the power, 2015-02-19 16:05:09]

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

[commit-bot: I haz the power, 2015-02-19 16:05:10]

Try jobs failed on following builders:
  v8_linux64_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_rel/builds/3129)

[rossberg, 2015-02-19 16:27:06]

New patchsets have been uploaded after l-g-t-m from arv@chromium.org

[rossberg, 2015-02-19 16:27:17]

The CQ bit was checked by rossberg@chromium.org

[commit-bot: I haz the power, 2015-02-19 16:28:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/932283003/20001

[commit-bot: I haz the power, 2015-02-19 16:49:19]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-19 16:49:33]

Patchset 2 (id:??) landed as
https://crrev.com/7b49ed658cec317ad8009b08812f8aa42abebb71
Cr-Commit-Position: refs/heads/master@{#26755}

[marja, 2015-02-20 17:08:55]

marja@chromium.org changed reviewers:
+ marja@chromium.org

[marja, 2015-02-20 17:08:55]

I was staring at this change for a long time and I don't understand it. Why does
it work? Because there's some other code somewhere which says that consts are
not put to the global object?

How does const (or function) resolution across scripts work? Obviously it works
somehow since consts work :) (But how can we add a paranoid test that we don't
break function resolution across scripts?)

[rossberg, 2015-02-23 12:48:37]

On 2015/02/20 17:08:55, marja wrote:
> I was staring at this change for a long time and I don't understand it. Why
does
> it work? Because there's some other code somewhere which says that consts are
> not put to the global object?
> 
> How does const (or function) resolution across scripts work? Obviously it
works
> somehow since consts work :) (But how can we add a paranoid test that we don't
> break function resolution across scripts?)

The CONST and LET variable kinds already implement lexical scoping, and lexical
scoping works across script (covered by tests). Otherwise we wouldn't have
shipped that. :)  So this works out of the box -- it would have been rather
alarming if it didn't.

(Currently we also have CONST_LEGACY, which is not lexical, and puts bindings on
the global object instead. That is going to go away eventually.)