Custos_engraver crash with no explicit pitches

[Simon Albrecht]

Hello everyone,

found this while creating a minimal example. The following code crashes 
on both 2.24.0 and 2.25.2:

%%%%%%%%%%%%%%%%
\version "2.24.0"

\new Staff \with {
  \consists Custos_engraver
} { 1 \break r1 1 }
%%%%%%%%%%%%%%%%

Not sure it’s ever going to trigger in real-life situations, but it’s a 
crash without error handling. “Output code 11.”

Best, Simon