5740d9f714
For x86_64, this can remove a REX prefix resulting in smaller code when manipulating globals of type i32, as we move them between backing store via cpu_env, aka TCG_AREG0. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Emilio G. Cota <cota@braap.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>