Test Coverage for cl_khr_device_enqueue_local_arg_types

There is currently no test coverage for [cl_khr_device_enqueue_local_arg_types](https://www.khronos.org/registry/OpenCL/specs/2.2/html/OpenCL_Ext.html#cl_khr_device_enqueue_local_arg_types).

This extension also does not appear to be supported by Clang, see: https://godbolt.org/z/rha8fy

This issue is to track test development for this feature if an implementor decides to support this extension in the future.

This was originally tracked by the item "Confirm: nothing needed for cl_khr_device_enqueue_local_arg_types?" in #773.

Start by reading the linked OpenCL extension specification and the original tracking item in issue #773. Then inspect the OpenCL-CTS test structure to identify where extension coverage belongs; done means adding tests for cl_khr_device_enqueue_local_arg_types if an implementor supports it.

Written by the indexing model from the issue text.