Completely mechanical changes:
- Explicit @objc in a few places
- Some imported APIs changed
- For the mix-and-match tests, just test version 4/5 instead of 3/4
We can't reliably reject raw values in an NS_ENUM's init(rawValue:), because the enum may have SPI or future values we don't statically know about. Fixes https://twitter.com/autorelease/status/524698585406124033
Swift SVN r23817