[cvs-nhc98] When an 'opendir' failed it created a foreign object with

malcolm: Tue Apr 23 15:42:46 CEST 2002 Update of /usr/src/master/nhc/src/prelude/Directory In directory hinken:/tmp/cvs-serv14575/src/prelude/Directory Modified Files: GetDirectoryContents.gc Log Message: When an 'opendir' failed it created a foreign object with a 'cval' of 'NULL'. During garbage collection the finalizer 'closedir' was be called with a 'NULL' pointer argument, leading to a core dump. This patch makes closedir aware of failed 'opendir' and also uses the haskell greencard version as the finalizer instead of using the C library function directly. (From Thomas Nordin.)