[Beignet] [PATCH] utests: add utest to double version of log, log2, log10

[Song, Ruiling]

> +static void builtin_double_logx(void)
> +{
> +  // Setup kernel and buffers
> +  int k, i, index_cur;
> +  unsigned long gpu_data[max_function * count_input] = {0};
> +  float diff;
> +  char log[256] = {0};
> +
> +  OCL_CREATE_KERNEL("builtin_double_logx");
> +

I just thought of a problem. Seems that you need to check whether cl_khr_fp64 extension is supported or not.
For older generation hardware. It is not possible to support double. Then this utest will certainly fail.
So, I think you need to add the this extension check for all the double test cases.

Thanks!
Ruiling