target/s390x: Split out gen_ri2

Use tcg_constant_i64.  Adjust in2_mri2_* to allocate a new
temporary for the output, using gen_ri2 for the address.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
1 file changed