Extended functions for OCaml Unix module (runtime package)

 Thin bindings to various low-level system APIs (often non-portable)
 which are not covered by Unix module.
 .
 Example functions:
  * uname
  * statvfs
  * fsync
  * fadvise
  * fallocate
  * atfile
  * dirfd
  * eventfd
  * signalfd
  * ...
 .
 This package contains the shared runtime libraries.