swift234

IRGen: Don't special-case retain/release for multi-payload enums with multiple simple cases.

The simple cases after the first one end up getting assigned invalid non-null pointer representations that *_retain and *_release aren't written to expect. We checked for this case incorrectly by checking the size of vector arguments that had been std::move'd from. Oops. Fixes rdar://problem/18118396.

Swift SVN r21612