Extend rlib xferrecv API
Robert Sprowson authored
Add xferrecv_last_ref to get hold of the Wimp message id of the request for a scrap file data save, when the RAM transfer gets no reply. This is useful to allow the data save to be distinguished from a file being dragged to an application, without having to resort to string compares against <wimp$scrap>.
SWIOptions:
 Also add RTC to SWI exports, and remove redundant ones.
armsys.c:
 Treat cmd_string as a pointer.
xferrecv.c/.h/rl_entries:
 New function xferrecv_last_ref.

Version 5.84. Tagged as 'RISC_OSLib-5_84'
97c92ee5