bowerbird and hammerkop didn't like commit a02b37fc. They're still
using the old 3rd build system that is not tested by CI. It's due for
removal in the 17 cycle IIUC but in the meantime I guess the new
codegen script needs to be invoked by something under src/tools/msvc?
varlena.obj : error LNK2019: unresolved external symbol
unicode_category referenced in function unicode_assigned
[H:\\prog\\bf\\root\\HEAD\\pgsql.build\\postgres.vcxproj]
