Transmit a sysEx to the midi device.
The given msg MUST NOT contain the usual SysEx frame, i.e. do NOT include the leading 0xF0 and the trailing 0xF7.
Furthermore, the maximal supported length of a SysEx is 254 bytes. Passing longer buffers can lead to undefined behavior (most likely, a crash).
Referenced by Scumm::IMuseInternal::terminate().