"watchdog function in the Arduino Library that would allow processor-independent implementation of such function"
Ah. It depends on whether that means "processor-independent within the AVR family" or "processor-independent within all CPUs that implement an arduino-like library." Usually a watchdog is a pretty architecture-dependent thing; not all chips support the same timeouts, some have a "window" of allowed reset times, etc...
The avr-libc watchdog functions are probably OK for within the AVR family...