ref: f5b19906047cd318f901557731021ad136e5643f
dir: /test/link/section-union/split-data.out/
error: Section "mutually-overlaid data" is of type ROM0, which cannot be unionized --- error: <stdin>(18): Cannot declare ROM sections as UNION FATAL: <stdin>(18): Cannot create section "mutually-overlaid data" (1 error)