remove old MakeWeak

remove old MakeWeak

R=svenpanne@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=14911

[dcarney, 2013-05-29 16:45:35]

we have no deprecation option with this one, it must simply be deleted

[Sven Panne, 2013-06-03 07:35:42]

lgtm

[dcarney, 2013-06-03 08:17:16]

Committed patchset #1 manually as r14911 (presubmit successful).

[jacobsa, 2014-07-01 00:12:46]

I'm looking at this code review because I own a project that embeds v8 (Google
JS Test) and am trying to figure out how the hell I make it build with the
latest version of v8 on my system, puzzling through at least three different
backwards-incompatible API changes. This is a real pain in the ass to have to
do every few months.

The last one for me to figure out is MakeWeak, so I'm digging through 'git
blame' to try to infer what I should be using instead. And I land on this code
review thread, which has no context whatsoever -- "remove old MakeWeak" is not
helpful to me in this code archaeology.

You guys could make this a lot easier on people like me if for each
backwards-incompatible API change you wrote up a short document saying:

* What is being deleted.
* Why it is being deleted.
* What users of the deleted API should switch to.
* (Optionally) some before and after sample code.

and then published such documents somewhere central, and linked to them as
context for each change like this one.