The maximum number of RxBuffer structs that could be sent in a single FIDL
message while staying within the maximum message size enforced by the
bindings.
The maximum number of RxSpaceBuffer structs that could be sent in a single
FIDL message while staying within the maximum message size enforced by the
bindings.
The maximum number of TxBuffer structs that could be sent in a single FIDL
message while staying within the maximum message size enforced by the
bindings.
The maximum number of TxResult structs that could be sent in a single FIDL
message while staying within the maximum message size enforced by the
bindings.