DP: Include `client_id` as a MUST.

[Nat Sakimura]

draft-ietf-oauth-jwsreq-11 states on page 7.

To sign, JSON Web Signature (JWS) [RFC7515] is used. The result is a JWS signed JWT [RFC7519]. If signed, the Authorization Request Object SHOULD contain the Claims "iss" (issuer) and "aud" (audience) as members, with their semantics being the same as defined in the JWT [RFC7519] specification.

This should be changed into:

To sign, JSON Web Signature (JWS) [RFC7515] is used. The result is a JWS signed JWT [RFC7519]. If signed, the Authorization Request Object MUST contain a client_id parameter and SHOULD contain a "iss" (issuer) parameter and an "aud" (audience) parameter, with their semantics being the same as defined in the JWT RFC7519] specification.

[Nat Sakimura]

Propose REJECT.

client_id is already REQUIRED in RFC6749.