Introduced in OpenMP 6.0, the device UID shall be a unique identifier of
a device on a given system. (Not necessarily a UUID.) Since it is not
guaranteed that the (U)UIDs defined by the device vendor libraries, such
as HSA, do not overlap with those of other vendors, the device UIDs in
offload are always combined with the offload plugin name. In case the
vendor library does not specify any device UID for a given device, we
fall back to the offload-internal device ID.
The device UID can be retrieved using the `llvm-offload-device-info`
tool.

This is the total number of work items that the device supports (the
equivalent work group properties are for only a single work group).

On my system, this will be "Radeon RX 7900 GRE" rather than "gfx1100". For Nvidia, the product name and device name are identical.

Add the following properties in Offload device info:
* VENDOR_ID
* NUM_COMPUTE_UNITS
* [SINGLE|DOUBLE|HALF]_FP_CONFIG
* NATIVE_VECTOR_WIDTH_[CHAR|SHORT|INT|LONG|FLOAT|DOUBLE|HALF]
* MAX_CLOCK_FREQUENCY
* MEMORY_CLOCK_RATE
* ADDRESS_BITS
* MAX_MEM_ALLOC_SIZE
* GLOBAL_MEM_SIZE

Add a bitfield option to enumerators, allowing the values to be
bit-shifted instead of incremented. Generate the per-type enums using
`foreach` to reduce code duplication.

Use macros in unit test definitions to reduce code duplication.

`MAX_WORK_GROUP_SIZE` now represents the maximum total number of work
groups the device can allocate, rather than the maximum per dimension.
`MAX_WORK_GROUP_SIZE_PER_DIMENSION` has been added, which has the old
behaviour.

This is a generated file which contains a macro for all Device Info
keys. This is visible to the plugin interface so that it can use the
definitions in a future patch.

This adds a new device info query for the maximum workgroup/block size
for each dimension.

Summary:
We use this sepcial type to indicate a host value, this will be refined
later but for now it's used as a stand-in device for transfers and
queues. It needs a special kind because it is not a device target as the
other ones so we need to differentiate it between a CPU and GPU type.

Fixes: https://github.com/llvm/llvm-project/issues/141436