As the bug appears to have been fixed I'm closing the bug report.
- bug#39206: lib/unistr/u8-uctomb.c fails to compile Andreas Schwab
- bug#39206: warning in lib/unistr/u8-uctomb.c Bruno Haible
- bug#39206: warning in lib/unistr/u8-uctomb.c Andreas Schwab
- bug#39206: lib/unistr/u8-uctomb.c fails to compile Paul Eggert
