Implement missing function: `hipEventQuery`

[fwyzard]

Would it be possible to implement hipEventQuery ?

According to the current HIP documentation:

hipError_t hipEventQuery(hipEvent_t event)

Query the status of the specified event. This function will return hipSuccess if all commands in the appropriate stream (specified to hipEventRecord()) have completed.

The documentation goes on to say that

If that work has not completed, or if hipEventRecord() was not called on the event, then hipErrorNotReady is returned.

However this is not what I observe: hipEventQuery() returns hipSuccess for an event that has been just created, before hipEventRecord() was ever called with it.

[fwyzard]

See also ROCm/hip#3383 for the HIP documentation.

[fwyzard]

See #56 for an attempt to implement hipEventQuery().