1619ee9e93
For INDEX_op_bswap16_i64, use 64-bit instructions so that we can easily provide the extension to 64-bits. Drop the special case, previously used, where the input is already zero-extended -- the minor code size savings is not worth the complication. Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>