Merge remote-tracking branch 'origin/master' into masters/weak_mem

theories/lang/lock.v

theories/lifetime/lifetime_sig.v

theories/lifetime/model/creation.v

theories/lifetime/model/definitions.v

theories/logic/gps.v

theories/typing/base.v

theories/typing/function.v

theories/typing/lib/arc.v

theories/typing/lib/mutex/mutex.v

theories/typing/lib/mutex/mutexguard.v

theories/typing/lib/rc/rc.v

theories/typing/lib/rc/weak.v

theories/typing/lib/refcell/refmut.v

theories/typing/lib/rwlock/rwlock.v

theories/typing/lib/rwlock/rwlock_code.v

theories/typing/lib/rwlock/rwlockreadguard_code.v

theories/typing/lib/rwlock/rwlockwriteguard.v

theories/typing/own.v

theories/typing/product.v

theories/typing/product_split.v