[REG][FTBFS][Clang 15][C++2b] QtWayland compilation of generated files throws several errors

Can't bisect because older qtwayland.git no longer compiles against current qtbase, so filing bug report instead of trying to fix it myself. Must be something new, a few weeks ago, it still worked with the same setup whereas now I get errors such as:

qwayland-wayland.cpp:1444:11: error: no member named 'wl_surface_offset' in the global namespace
::wl_surface_offset(
~~^
qwayland-wayland.cpp:1852:9: error: excess elements in struct initializer
wl_pointer::handle_axis_value120,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
qwayland-wayland.cpp:2409:9: error: excess elements in struct initializer
wl_output::handle_name,
^~~~~~~~~~~~~~~~~~~~~~
3 errors generated.

See attached log for configuration details and the full list of errors.