[fuchsia] swap out deprecated flag name

FDIO_SPAWN_CLONE_LDSVC was replaced with FDIO_SPAWN_DEFAULT_LDSVC, as it no
longer always means clone.

Fuchsia Bug: ZX-3031

Change-Id: I62ace1e8b9f87440adf7aea31424137a47d16303
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/105400
Reviewed-by: Zach Anderson <zra@google.com>
Commit-Queue: Zach Anderson <zra@google.com>
Auto-Submit: James Tucker <raggi@google.com>
diff --git a/runtime/bin/process_fuchsia.cc b/runtime/bin/process_fuchsia.cc
index 50ea7fed..087d875 100644
--- a/runtime/bin/process_fuchsia.cc
+++ b/runtime/bin/process_fuchsia.cc
@@ -619,7 +619,7 @@
     LOG_INFO("ProcessStarter: Start() Calling fdio_spawn_vmo\n");
     zx_handle_t process = ZX_HANDLE_INVALID;
     char err_msg[FDIO_SPAWN_ERR_MSG_MAX_LENGTH];
-    uint32_t flags = FDIO_SPAWN_CLONE_JOB | FDIO_SPAWN_CLONE_LDSVC;
+    uint32_t flags = FDIO_SPAWN_CLONE_JOB | FDIO_SPAWN_DEFAULT_LDSVC;
     status = fdio_spawn_vmo(ZX_HANDLE_INVALID, flags, vmo, program_arguments_,
                             program_environment_, actions_count, actions,
                             &process, err_msg);