Use a different magic number (0x1face64) for 64-bit interface files.
This will prevent us trying to read the dictionary out of a 32-bit
interface file on a 64-bit machine.
-- --------------------------------------------------------------
initBinMemSize = (1024*1024) :: Int
+
+#if WORD_SIZE_IN_BITS == 32
binaryInterfaceMagic = 0x1face :: Word32
+#elif WORD_SIZE_IN_BITS == 64
+binaryInterfaceMagic = 0x1face64 :: Word32
+#endif
getBinFileWithDict :: Binary a => FilePath -> IO a
getBinFileWithDict file_path = do