support initializer_list ctor for simd_array because the size is well-defined
support initializer_list ctor for simd_array because the size is well-defined

VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc,VcDevel/Vc,chr-engwer/Vc,VcDevel/Vc,chr-engwer/Vc