Hi Li,
the complete safety concept requires an external PMIC or at least a WDT as pure minimum. The WDT will detect endless loops and reset the part a number of times until it completely disables the MCU. NXP PMICs support this, the number of POR resets can be configured and read after boot. Please consult the RM/SM of the used PMIC.
If permanent HW failures occur causing an endless loop there is a severe problem so completely disable the MCU is appropriate as you can assume a recovery is not possible anymore. Customers need to handle this situation themselves as this is application dependent.
Regards,
Bas