* config/rx/rx.opt (-mjsr): Add.
* config/rx/predicates.md (rx_call_operand): Avoid overflowing
calls when -mjsr.
* config/rx/rx.c (rx_function_ok_for_sibcall): Likewise for
overflowing jumps.
* doc/invoke.texi (-mjsr): Document it.

From-SVN: r231439