[wasm] Add a JavaScript utility to make it easier to build WASM modules from JavaScript.

[wasm] Add a JavaScript utility to make it easier to build WASM modules from JavaScript.

This is a reland of https://codereview.chromium.org/1762203002/

R=ahaas@chromium.org,binji@chromium.org,seththompson@chromium.org
BUG=

Committed: https://crrev.com/aa5770805060a347c6b650634c736ba34ab61728
Cr-Commit-Position: refs/heads/master@{#34519}

[ahaas, 2016-03-07 09:35:17]

lgtm

[titzer, 2016-03-07 09:43:33]

The CQ bit was checked by titzer@chromium.org

[commit-bot: I haz the power, 2016-03-07 09:43:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1774463002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1774463002/1

[commit-bot: I haz the power, 2016-03-07 09:45:53]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-07 09:46:46]

Description was changed from

==========
[wasm] Add a JavaScript utility to make it easier to build WASM modules from
JavaScript.

This is a reland of https://codereview.chromium.org/1762203002/

R=ahaas@chromium.org,binji@chromium.org,seththompson@chromium.org
BUG=
==========

to

==========
[wasm] Add a JavaScript utility to make it easier to build WASM modules from
JavaScript.

This is a reland of https://codereview.chromium.org/1762203002/

R=ahaas@chromium.org,binji@chromium.org,seththompson@chromium.org
BUG=

Committed: https://crrev.com/aa5770805060a347c6b650634c736ba34ab61728
Cr-Commit-Position: refs/heads/master@{#34519}
==========

[commit-bot: I haz the power, 2016-03-07 09:46:47]

Patchset 1 (id:??) landed as
https://crrev.com/aa5770805060a347c6b650634c736ba34ab61728
Cr-Commit-Position: refs/heads/master@{#34519}

[Michael Achenbach, 2016-03-07 09:59:59]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1768963002/ by machenbach@chromium.org.

The reason for reverting is: [Sheriff] Problem is not fixed:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20shared/build....