Add break for default cases

Visual Studio has an option to search all files in a solution, so I
did a search in there for "default:" looking for any missing break
statements.

I've left out default statements that return something, and that throw
something, even if via ThrowInvalidType. UNREACHABLE leads towards throw

R_THROW macro leads towards a return

src/yuzu_cmd/emu_window/emu_window_sdl2_vk.cpp

@@ -84,6 +84,7 @@ EmuWindow_SDL2_VK::EmuWindow_SDL2_VK(InputCommon::InputSubsystem* input_subsyste
     default:
         LOG_CRITICAL(Frontend, "Window manager subsystem not implemented");
         std::exit(EXIT_FAILURE);
+        break;
     }
 
     OnResize();