hipFile buffer registration

Unlike file registration, registering a buffer is optional.

Buffer registration stores the device base pointer and length in bytes in an internal map. During hipFileRead() and hipFileWrite(), offsets and sizes are validated against the map without requiring HIP pointer lookup. This is useful for situations where the buffer is reused for multiple transfers or when predictable bounds checks are needed.

Buffers are registered with hipFileBufRegister(). If hipFileBufRegister() is called, it must be called before a call to hipFileRead() or hipFileWrite(). Only hipMemoryTypeDevice buffers can be registered.

When a registered device buffer is passed to hipFileRead() or hipFileWrite(), hipFile looks up the tracked entry and validates the I/O range against the registered length.

When an unregistered device buffer is passed, hipFile resolves the pointer at the time of the I/O operation.

Call hipFileBufDeregister() when the buffer is no longer needed.