* real.c (sticky_rshift_significand): Return inexact, don't
        or it in immediately.
        (sub_significands): Accept incomming carry.
        (div_significands, rtd_divmod): Update for sub_significands change.
        (round_for_format): Update for sticky_rshift_significand change.
        (do_add): Don't involve the inexact bit in addition, do give the
        inexact bit as the subtraction carry-in.
        (encode_internal, decode_internal, real_internal_format): New.
        * real.h (real_internal_format): Declare.

From-SVN: r58396