write-char and put-char inlined incorrectly in v0.96

[will]

Reported by Ray Racine.

The write-char procedure evaluates its first argument twice when inlined, and the put-char procedure evaluates its second argument twice when inlined. This is a bug in the inlined code for put-char in common.imp.sch. Test case:

(let ((s "abcdefgh"))
  (define echochars
    (lambda (ip op)
      (let loop ((ch (peek-char ip)))
        (cond ((eof-object? ch)
               (get-output-string op))
              (else
               (write-char (read-char ip) op)
               (loop (peek-char ip)))))))
  (echochars (open-input-string s) (open-output-string)))

should return "abcdefgh", but returns "bdfh" in v0.96.

[will]

Fixed by changeset:5272 and v0.961.