Flag a discriminator property that is defined as an extensible enum

[mikekistler]

oav should issue an error message for a property that is defined as the discriminator for a schema when it is an extensible enum, I.e.x-ms-enum: { modelAsString: true }, because changing the set of values for a discriminator is a breaking change.

[raych1]

Hi @mikekistler , sorry for the late response. Removing enum values is breaking change while adding new value is allowed in new api version. This validation is already covered on breaking change review.