[R6RS] non-opaque record equality

[William D Clinger]

Matthew asked:
> Would it make sense for two records could be `equal?' when 
> 
>  1. they are instances of the same *non-opaque* record type, and 
> 
>  2. their corresponding field values are all `equal?'
> 
> ? This change seems consistent with the SRFI's reflection support on
> non-opaque records.

That sounds right to me.

Will