from armv8.c:1377
static struct reg_data_type_vector aarch64_vector_types[] = {
{aarch64_vector_base_types + 0, 2},
{aarch64_vector_base_types + 1, 2},
{aarch64_vector_base_types + 2, 2},
{aarch64_vector_base_types + 3, 4},
{aarch64_vector_base_types + 4, 4},
{aarch64_vector_base_types + 5, 4},
{aarch64_vector_base_types + 6, 8},
{aarch64_vector_base_types + 7, 8},
{aarch64_vector_base_types + 8, 16},
{aarch64_vector_base_types + 9, 16},
{aarch64_vector_base_types + 10, 01},
{aarch64_vector_base_types + 11, 01},
};