Since we have "main" like functions in the devices crate for vhost-user
devices, we need to use ExitContext & Exit there. This wasn't possible
with the existing location in the crosvm/main crate because crosvm ->
devices so we can't have devices -> crosvm. This CL moves exit to a new
crate, crosvm_cli, where it can be used by all interested consumers.
BUG=b:253348635
TEST=builds
Change-Id: Ia06d9dee2cd5826ea20a7fb3a0c2a53c58e2ff1d
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3960854
Commit-Queue: Noah Gold <nkgold@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
