[[ARM/AArch64][testsuite] 18/36] Add vsli_n and vsri_n tests.

[Tejas Belagod]

> +
> +void vsri_extra(void)
> +{
> +    /* Test cases with maximum shift amount (this amount is different
> +     * from vsli.  */
> +

Nit. Comment Formatting. Similarly, few other places.

Otherwise, LGTM.

Tejas.