pshmem.h now includes shmem.h (since open-mpi/ompi@f46130cd20) and some macros were removed at that time.
Use the OSHMEM_HAVE_C11 macro (defined in shmem.h) instead of the
previous OSHMEMP_HAVE_C11 macrso previously defined in pshmem.h
Signed-off-by: Gilles Gouaillardet <gilles@rist.or.jp>
(cherry picked from commit 5ea939aa542605503b7926a44df10e23a344d063)
9c5d4bb3b9