Error when slashedGrace follows grace

[Knute Snortum]

The following snippet will cause an error in version 2.22.2:

%%%
\version "2.22.2"

\relative {
  c''2. \grace { b16[ c] } \slashedGrace { d8 } c4\trill |
}
%%%

This error does not show up in 2.23.9, so I don't know if there's any
action to take, but I thought I'd document it here.

--
Knute Snortum