[FileManager] _attributesOfItem: use creationDate from the stat exten…

…sion in

NSURL rather than repeating that logic

The last case in stat.creationDate also works for Android.

Sources/Foundation/FileManager.swift

@@ -544,14 +544,7 @@ open class FileManager : NSObject {
         result[.creationDate] = creationDate
 #else
         let s = try _lstatFile(atPath: path)
-        // Darwin provides a `st_ctimespec` rather than the traditional Unix
-        // `st_ctime` field.  Since `st_ctime` is more traditional, special case
-        // Darwin platforms and convert the timespec to the absolute time.
-#if os(iOS) || os(macOS) || os(tvOS) || os(watchOS)
-        result[.creationDate] = Date(timespec: s.st_ctimespec)
-#else
-        result[.creationDate] = Date(timeIntervalSince1970: TimeInterval(s.st_ctime))
-#endif
+        result[.creationDate] = s.creationDate
 #endif
 
         result[.size] = NSNumber(value: UInt64(s.st_size))