[SYCL][ABI-break] Remove unused sycl::kernel methods

[againull]

Removing ext_oneapi_get_info(sycl::queue q) overloads and cleaning up extension doc and tests accordingly.
Also removed unused getNativeImpl.

[againull]

According to @0x12CC, ext_oneapi_get_info(sycl::queue q) overloads are unusable because the underlying L0 API requires the WG size to return a valid query result and these API does not provide it.

[gmlueck]

According to @0x12CC, ext_oneapi_get_info(sycl::queue q) overloads are unusable because the underlying L0 API requires the WG size to return a valid query result and these API does not provide it.

Can you explain this more? In particular, it seems like max_work_group_size should be implementable because it's the same query as info::kernel_device_specific::work_group_size (which we do support). What is the "underlying L0 API" you refer to here?

Also, do you know why "sycl_ext_oneapi_launch_queries" is "proposed" rather than "experimental"? According to internal tracker CMPLRLLVM-61694, it has been implemented already.

[0x12CC]

According to @0x12CC, ext_oneapi_get_info(sycl::queue q) overloads are unusable because the underlying L0 API requires the WG size to return a valid query result and these API does not provide it.

Can you explain this more? In particular, it seems like max_work_group_size should be implementable because it's the same query as info::kernel_device_specific::work_group_size (which we do support). What is the "underlying L0 API" you refer to here?

The context for this is in the comments of GSD-10327. My understanding is that zeKernelSuggestMaxCooperativeGroupCount requires the WG size and SLM size to return a valid result. The original queries did not work since these additional parameters were not provided to L0. The SYCL query was updated in #14333.

[gmlueck]

The context for this is in the comments of GSD-10327. My understanding is that zeKernelSuggestMaxCooperativeGroupCount requires the WG size and SLM size to return a valid result. The original queries did not work since these additional parameters were not provided to L0. The SYCL query was updated in #14333.

Ironically, I was just looking at that this morning. You are talking about the max_num_work_groups query. However, this PR removes max_work_group_size and max_work_item_sizes, which are different queries.