Turn message property of the error object into a data property.

Turn message property of the error object into a data property.

R=svenpanne@chromium.org
BUG=

Committed: https://code.google.com/p/v8/source/detail?r=12908

[Yang, 2012-11-08 15:29:57]

On 2012/11/08 15:26:14, Yang wrote:

This change includes:

- Format the message string when the error object is constructed, instead of
doing it lazily. Performance impact should be low.
- Turn the message dictionary into a object literal.
- Pass message type and formatting arguments as string and array instead of
bundled into a JSMessageObject. This makes some runtime calls to extract the
values obsolete.
- A bug discovered in proxies.js has been filed in v8:2398

[Sven Panne, 2012-11-09 07:55:07]

LGTM with a nit

http://codereview.chromium.org/11368142/diff/1/src/messages.cc
File src/messages.cc (right):

http://codereview.chromium.org/11368142/diff/1/src/messages.cc#newcode158
src/messages.cc:158: ASSERT(data->IsJSMessageObject());
No need for this ASSERT, all cast methods do this implicitly.