Revert "io.directories.unix: switch to readdir(3) since readdir_r(3) is deprecated"
Revert "io.directories.unix: switch to readdir(3) since readdir_r(3) is deprecated"

This reverts commit e0531ea85337e9d1e5af26568436ea23bdaf8e34.

tgunr/factor,factor/factor,mrjbq7/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,factor/factor,tgunr/factor,mrjbq7/factor,tgunr/factor,factor/factor,factor/factor,factor/factor,factor/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,tgunr/factor