Update our list of distros a bit.
Update our list of distros a bit.

- Debian jessie will be released this month, add the next testing version to the list.
- RHEL7 was released last june.
- Ubuntu utopic was released last october, vivid will follow later this month.

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@234149 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang