Add ScriptID field into ScriptOrigin class.
Anonymous script has empty resource name. To identify this script we need its id.

R=ulan@chromium.org, yangguo@chromium.org

Review URL: https://codereview.chromium.org/363553005

Patch from Alexey Kozyatinskiy <kozyatinskiy@google.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22248 ce2b1a6d-e550-0410-aec6-3dcde31c8c00