MSVC now says this on master: [17:48:12.446] c:\cirrus\src\backend\utils\adt\pg_locale.c(2912) : warning C4715: 'icu_language_tag': not all control paths return a value
CI doesn't currently fail for MSVC warnings, so it's a bit hidden. FWIW cfbot does show this with a ⚠ sign with its new system for grovelling through logs, which will now show up on every entry now that this warning is in master.
