[dynamo][compile-time] Collect guard debug stack info only with logs enabled (#120520)
Reduces backend=eager compile time from 33 to 19 seconds for `MobileBertForQuestionAnswering`. This also helps an internal model where guards.add function is taking 124 seconds.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120520
Approved by: https://github.com/mlazos
