pytorch

3276b512 - Add environment parse function that supports default value (#85563)

Add environment parse function that supports default value (#85563) We use "-2" to represent an unset environment variable. Now adding a util function to attach default value if environment variable is unset. Pull Request resolved: https://github.com/pytorch/pytorch/pull/85563 Approved by: https://github.com/rohan-varma, https://github.com/H-Huang