This was previously declined as CR.SE was in beta and migrations to beta sites are not allowed. CR is no longer in beta! Congratulations to CR!
I know we don't want too many migration paths, and we definitely don't want ones that are likely to leech away our good questions, but I think of all the technology related websites, the scope of Code Review actually has likely the least overlap with us of any others.
No part of our site scope is reviewing written completed code, architecture sure but not code.
And no part of code reviews site is doing anything else at all.
We don't get questions for this migration often, but I've seen ones migrated to SO with totally working code, just because we have a migration path to SO but not CR.