ref: eb4952c188fddf486adbdb98a82ea9e6123eaff1
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 errors)