[fix] composite compliance: quantile and nanquantile (#70894)
Summary:
Reference https://github.com/pytorch/pytorch/issues/69991
Refactored such that only `out` variant copies the result into `out` otherwise we just return the result of the composite functions as is.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70894
Reviewed By: samdow
Differential Revision: D33641742
Pulled By: zou3519
fbshipit-source-id: 671be13b31a7fff3afc0b7976706a5ecfc51ccac
(cherry picked from commit e7d5ac9af319be327adc16d2d7048139a4b2ddd3)
