[perl #69272] [TODO] Implement .succ and .pred for Rat

[Carl Mäsak via RT]

coke (>), masak (>>):
> > <masak> rakudo: my $a = 3/4; $a++
> > <p6eval> rakudo 5d3d3a: OUTPUT«Method 'succ' not found for invocant of
> > class 'Rat'␤»
> > * masak submits rakudobug
> 
> This seems to be working as of e52ed31e2fe1ab2fd4a661ebeda78a880bad1215
> 
> $ ./perl6 -e 'my $a = 3/4; say ++$a'
> 1.75

Indeed. moritz++ implemented it this morning. Resolving.