Merge pull request #772 from slavapestov/update-for-inlineable-diagnostics

Update for new rules on @inline(__always) function bodies

Author: slavapestov

Foundation/Data.swift

@@ -911,7 +911,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     public typealias Index = Int
     public typealias Indices = CountableRange<Int>
 
-    internal var _backing : _DataStorage
+    @_versioned internal var _backing : _DataStorage
 
     // A standard or custom deallocator for `Data`.
     ///