Implement device keyword into can_cast, result_type

[ndgrigorian]

The array API standard will soon require the device keyword be added to can_cast and result_type

See:
data-apis/array-api#691

[kgryte]

@ndgrigorian Following up here, it is not guaranteed that the Array API standard will require device kwarg support, as there are some concerns as to whether such support is desirable. If you have particular thoughts on whether it should be required, please provide that input on the PR and/or associated issue. Thanks!

[oleksandr-pavlyk]

It has been decided against implementing device keyword in these functions. When all arguments are dtype, full type promotion graph is to be used. When some arguments are arrays, devices must be the same, and the device-specific type promotion graph is to be used.

Hence, the recommended usage is xp.can_cast( array, to_dtype) rather than xp.can_cast(array.dtype, to_dtype).

We still should adjust implementation of dpctl.tensor.can_cast and dpctl.tensor.result_type to conform to this specification.

[ndgrigorian]

As the array API has decided against this, I will close this issue.

#1488 will also make these functions device-aware.