Right now, let's just support memfd. We could support other shared
memory types later.
vtest adaption based on following QEMU files:
qemu/include/qemu/memfd.h
qemu/util/memfd.c
v2: - memfd --> shm
- don't call fcntl(fd, F_ADD_SEALS) because it fails under callgrind
for some reason:
==8161== Warning: unimplemented fcntl command: 1033
vtest_new_shm called fcntl which failed (-22)
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-By: Gert Wollny <gert.wollny@collabora.com>