[[ARM/AArch64][testsuite] 13/36] Add vmla_n and vmls_n tests.

[Tejas Belagod]

> +VECT_VAR_DECL(expected,poly,8,8) [] = { 0x33, 0x33, 0x33, 0x33,
> +                                       0x33, 0x33, 0x33, 0x33 };
> +VECT_VAR_DECL(expected,poly,16,4) [] = { 0x3333, 0x3333, 0x3333, 0x3333 };

No poly vmlx_n, otherwise LGTM.

Tejas.