Some time ago I made a change to merge together the memory scope
definitions used by mmap (MAP_{PRIVATE,SHARED}) and lock objects
(PTHREAD_PROCESS_{PRIVATE,SHARED}). Though that sounded pretty smart
back then, it's backfiring. In the case of mmap it's used with other
flags in a bitmask, but for locking it's an enumeration. As our plan is
to automatically generate bindings for other languages, that looks a bit
sloppy.
Change all of the locking functions to use separate flags instead.
Obtained from: https://github.com/NuxiNL/cloudabi
34d932442d