[fuchsia] Propagate UTC handle when launching processes

Fuchsia is migrating from a kernel managed UTC clock to a userspace
managed UTC clock. A process must be launched with a handle to the
userspace clock in order to read it. This change updates sshd to launch
child processes with a cloned handle to its UTC clock.

Testing: Manually verify that log_listener can read UTC time from the
userspace clock with changes in
https://fuchsia-review.googlesource.com/c/fuchsia/+/448439

Change-Id: I4c80f7b0af6a2ac0f11734eb291de20e2906e59a
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/openssh-portable/+/449657
Reviewed-by: Adam Perry <adamperry@google.com>
Reviewed-by: John Grossman <johngro@google.com>
Commit-Queue: Satsuki Ueno <satsukiu@google.com>
diff --git a/fuchsia/fuchsia-compat.c b/fuchsia/fuchsia-compat.c
index 225712d..3b70dd1 100644
--- a/fuchsia/fuchsia-compat.c
+++ b/fuchsia/fuchsia-compat.c
@@ -234,7 +234,7 @@
       },
   };
 
-  uint32_t flags = FDIO_SPAWN_CLONE_JOB | FDIO_SPAWN_CLONE_NAMESPACE;
+  uint32_t flags = FDIO_SPAWN_CLONE_JOB | FDIO_SPAWN_CLONE_NAMESPACE | FDIO_SPAWN_CLONE_UTC_CLOCK;
   return fdio_spawn_etc(ZX_HANDLE_INVALID, flags, argv[0], argv, (const char* const*)env, 4,
                         actions, proc, err_msg);
 }