[PATCH] OpenCL kernel semantic checks

Hi everybody,

I would like to propose a patch for two OpenCL semantic checks:
1) the __kernel keyword can only be applied to functions,
2) kernel must return void: described in section 6.8.j of the OpenCL manual

I took inspiration from the checks performed on the CUDA attributes performed
by Peter Collingbourne

Reviews are the welcome.

Thank you in advance

Alberto

kernel_sema.patch (2.5 KB)