fix build on windows with unix-compat-0.4.1.3

FileID type changed, needs Arbitrary instance.

On the plus side, getFileStatus on Windows now actually gets file id's,
not always 0, so direct mode is safer there now.

Utility/InodeCache.hs

@@ -40,6 +40,10 @@ import Common
 import System.PosixCompat.Types
 import Utility.QuickCheck
 
+#ifdef mingw32_HOST_OS
+import Data.Word (Word64)
+#endif
+
 data InodeCachePrim = InodeCachePrim FileID FileOffset EpochTime
 	deriving (Show, Eq, Ord)
 
@@ -204,6 +208,11 @@ instance Arbitrary InodeCache where
 			<*> arbitrary
 		in InodeCache <$> prim
 
+#ifdef mingw32_HOST_OS
+instance Arbitrary FileID where
+	arbitrary = fromIntegral <$> (arbitrary :: Gen Word64)
+#endif
+
 prop_read_show_inodecache :: InodeCache -> Bool
 prop_read_show_inodecache c = case readInodeCache (showInodeCache c) of
 	Nothing -> False