Metal: Fix Device::pendingCommands being freed under us
Metal: Fix Device::pendingCommands being freed under us

Kangz/nxt-standalone,googlearchive/nxt-standalone,googlearchive/nxt-standalone,Kangz/nxt-standalone,googlearchive/nxt-standalone,Kangz/nxt-standalone,Kangz/nxt-standalone,googlearchive/nxt-standalone