I'm looking at

        * numbers.c (guile_ieee_init): Use C99 INFINITY and NAN when
        available.  Test HAVE_DINFINITY and HAVE_DQNAN for those globals, in
        particular don't assume "defined (__alpha__) && ! defined (linux)"
        means OSF.  Remove "SCO" code, which was not really SCO specific and
        which John W. Eaton advises should be long past being needed.