RCB: ^M variable still bound on dynamic memory deletion message

^M memory (%MEM_PROC) is released, but some or all of the memory is still set as an argument for %RCB_CALL. Checking for this condition occurs only when the routine has been compiled with ‑qcheck. Message may be “Argument number was number" with, optionally, "RCB routine: routine nameELB name”.