Restore message when rethrowing in TryCatch.

Based on a patch contributed by Andrew Paprocki <andrew@ishiboo.com>.

R=jkummerow@chromium.org
BUG=
TEST=cctest/test-api/TryCatchNestedSyntax

Review URL: https://codereview.chromium.org/17694002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15408 ce2b1a6d-e550-0410-aec6-3dcde31c8c00