Comment 0 for bug 1874207

There are a couple of compiler warnings apparently caused by x11-Add-support-for-fractional-scaling-using-Randr.patch:

$ ninja
[297/1390] Generating meta-marshal_c with a custom command.
INFO: Reading ../src/meta-marshal.list...
[298/1390] Generating meta-marshal_h with a custom command.
INFO: Reading ../src/meta-marshal.list...
[427/1390] Compiling C object 'src/25a...ends_meta-monitor-config-manager.c.o'.
../src/backends/meta-monitor-config-manager.c: In function ‘assign_monitor_crtc’:
../src/backends/meta-monitor-config-manager.c:226:3: warning: enumeration value ‘META_LOGICAL_MONITOR_LAYOUT_MODE_GLOBAL_UI_LOGICAL’ not handled in switch [-Wswitch]
  226 | switch (data->config->layout_mode)
      | ^~~~~~
[471/1390] Compiling C object 'src/25a..._x11_meta-monitor-manager-xrandr.c.o'.
../src/backends/x11/meta-monitor-manager-xrandr.c: In function ‘meta_monitor_manager_xrandr_get_capabilities’:
../src/backends/x11/meta-monitor-manager-xrandr.c:1169:18: warning: ‘capabilities’ may be used uninitialized in this function [-Wmaybe-uninitialized]
 1169 | capabilities |= META_MONITOR_MANAGER_CAPABILITY_TILING;
      | ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[1390/1390] Linking target src/tests/mutter-headless-start-test.