binary-port?

[Ludovic Courtès]

Hello,

I just pushed 96128014bfaabe9e123c4f4928ce4c20427eaa53, which makes
‘binary-port?’ deterministic for ports intended to be binary.

However, I’m wondering whether we should not just squarely do away with
the binary/textual distinction, and just write:

  (define (binary-port? p) #t)

What do people with experience with pure R6RS code think?  Is the
distinction actually used, and how?

Thanks,
Ludo’.