Pre-fallback handshake roles are not preserved

[nazar-pc]

http://noiseprotocol.org/noise.html#fallback-patterns:

The initiator and responder roles from the pre-fallback handshake are preserved in the fallback handshake. Thus, the responder sends the first message in a fallback handshake.

However:

noise-c/tests/unit/test-handshakestate.c

Lines 584 to 587 in 6243290

	/* Fallback on the responder side */
	compare(noise_handshakestate_fallback(responder), NOISE_ERROR_NONE);
	compare(noise_handshakestate_get_role(initiator), NOISE_ROLE_INITIATOR);
	compare(noise_handshakestate_get_role(responder), NOISE_ROLE_INITIATOR);

noise-c/tests/unit/test-handshakestate.c

Lines 615 to 618 in 6243290

	/* Fallback on the initiator side */
	compare(noise_handshakestate_fallback(initiator), NOISE_ERROR_NONE);
	compare(noise_handshakestate_get_role(initiator), NOISE_ROLE_RESPONDER);
	compare(noise_handshakestate_get_role(responder), NOISE_ROLE_INITIATOR);

You can argue that this is an implementation detail, but still it would be better to not confuse those who use this library after reading the spec and introduce separate entity to indicate that fallback protocol is used.

UPD: I saw This function reverses the roles of initiator and responder., but this conflicts with the spec.