Out of context I can't be sure but it looks like a circuit to delay the rise of the regulator output as the 3.3V line rises.
C54 charging through R22 will cause a slight increase in voltage at the ADJ pin which in turn will trick it into thinking it has to reduce it's output voltage to maintain regulation. D1 will be to discharge C54 again when the power is removed. Once C54 is charged, the regulated voltage will be set only by R24 and R25. I would guess D2 is to limit the 'ADJ' voltage rise and also prevent back-flow into the delay components.
Brian.