Lifetime logic: rename shared borrows to atomic (persistent) borrows

_CoqProject

theories/lifetime/at_borrow.v

theories/lifetime/frac_borrow.v

theories/typing/lib/arc.v

theories/typing/lib/mutex/mutex.v

theories/typing/lib/mutex/mutexguard.v

theories/typing/lib/rwlock/rwlock.v

theories/typing/lib/rwlock/rwlock_code.v

theories/typing/lib/rwlock/rwlockreadguard.v

theories/typing/lib/rwlock/rwlockreadguard_code.v

theories/typing/lib/rwlock/rwlockwriteguard.v

theories/typing/lib/rwlock/rwlockwriteguard_code.v