Not just iDevices. Gaming consoles also have such restrictions. So do safety critical systems (flight control systems often have some kind of interpreter but never a JIT as far as I know). There are probably other examples.
Fast start absolutely does require an interpreter and it is true that the jump to JIT is very quick - but that jump never happens for a large number of run-once functions (like initialization code or data definition code). Having that interpreter also saves you memory, since initialization code tends to be quite large.
Fast start absolutely does require an interpreter and it is true that the jump to JIT is very quick - but that jump never happens for a large number of run-once functions (like initialization code or data definition code). Having that interpreter also saves you memory, since initialization code tends to be quite large.