* config/rx/rx.c (rx_conditional_register_usage): Do not warn if
no fixed registers are available for interrupt handlers. Do not
fix normal registers.
(MUST_SAVE_ACC_REGISTER): New macro.
(rx_get_stack_layout): Create a stack frame for fast interrupt
handlers, if necessary. Push extra registers if needed in order
to save the accumulator.
(rx_expand_prologue): Create a stack frame for fast interrupt
handlers, if necessary.
(rx_expand_builtin_mvfc): Handle the case where there is no
target.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@154903 138bc75d-0d04-0410-961f-82ee72b054a4