Refactor cl::sycl::info::device_type to allow bitwise operations internally

[sergey-semenov]

Current underlying values of cl::sycl::info::device_type do not lend themselves for bitwise operations.

enum class device_type : pi_uint64 {
  cpu         = PI_DEVICE_TYPE_CPU,
  gpu         = PI_DEVICE_TYPE_GPU,
  accelerator = PI_DEVICE_TYPE_ACC,
  // TODO: figure out if we need all the below in PI
  custom      = CL_DEVICE_TYPE_CUSTOM,
  automatic,
  host,
  all         = CL_DEVICE_TYPE_ALL
};

This leads to some unnecessarily complex logic of cl::sycl::detail::match_types and cl::sycl::detail::force_types, which could be merged into a single simpler method.

[mkinsner]

There is a wider issue, in that an OpenCL device can identify as more than one of these types (in a bitfield way):

In OpenCL, device types are a bitfield and not mutually exclusive.

device_type is a bitfield that identifies the type of OpenCL device.

In SYCL 1.2.1, device_type is an enum:

enum class device_type : unsigned int {

So the bitfield representation should probably be exposed through SYCL, and not just an internal implementation detail.

A proposal here or in the SYCL 1.2.1 spec repo to fix this, would be well received. There are simple solutions.

[keryell]

This is mentioned in https://gitlab.khronos.org/sycl/Specification/issues/261