[cvs-nhc98] Fix some race conditions with file Handles implemented as

malcolm: Mon Jun 11 18:13:17 CEST 2001 Update of /usr/src/master/nhc/src/prelude/IO In directory hinken:/tmp/cvs-serv16389/src/prelude/IO Modified Files: OpenFile.hs Log Message: Fix some race conditions with file Handles implemented as ForeignObjs. (1) A newly opened file could be garbage collected before being attached to the program graph. (2) A file closed by hClose could be finalised a second time when it was detached from the program graph.