remove outdated comment; NFC
remove outdated comment; NFC

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@258147 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit a27a3f756ce9ce1e8e7ca30395f02b5eeccdbe21)

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm