MSC: onexit_t onexit( onexit_t func )

	- prototype in stdlib.h

	- creates a list of functions to execute on normal program exit
	- on exit functions are executed LIFO
	- a max of 32 function can be registered
	- returns pointer to "func" on success;  NULL otherwise
	- this is a Microsoft/Lattice extension; ANSI uses atexit()

	- see  exit()  abort()