io.files.info.windows: Fix file-systems word in two ways. First, don't

io.files.info.windows: Fix file-systems word in two ways. First, don't
allocate 32k on the local alloc stack (which causes a 'double fault.')
Second, if the volume doesnt look up to a real path, don't make a dummy
object for that. volume
Use alien>native-string and native-string>alien wherever possible instead of
utf16n for Windows.