Add O_DIRECT to posix/fcntl.pxd (GH-3894)
Add O_DIRECT to posix/fcntl.pxd (GH-3894)

Closes https://github.com/cython/cython/issues/3242
scoder/cython,cython/cython,scoder/cython,scoder/cython,cython/cython,scoder/cython,da-woods/cython,da-woods/cython,da-woods/cython,cython/cython,cython/cython,da-woods/cython