As suggested by Anton Tagunov, eq and cmp now obey the

As suggested by Anton Tagunov, eq and cmp now obey the
encoding pragma (by remapping their byte argument if the
other argument is in Unicode).  Also fix a bug found by
Anton where ord undef under the encoding pragma would barf.
([ID 20020307.009] A null pointer dereference with 'use encoding')
Finally, use the nicer form of sv_recode_to_utf8.

p4raw-id: //depot/perl@15085