* config/rx/rx.c (rx_expand_epilogue): Add checks for sibcalls
        being used incorrectly.
        (rx_function_ok_for_sibcall): New function.  Do not allow indirect
        sibcalls, or sibcalls from interrupt functions.
        (TARGET_FUNCTION_OK_FOR_SIBCALL): Define.
        * config/rx/rx.md (sibcall): Convert to a define_expand.  Check
        for a MEM inside a MEM.
        (sibcall_value): Likewise.
        (sibcall_internal): New pattern containing old sibcall pattern.
        (sibcall_value_internal): Likewise.

From-SVN: r154671