sync handling of subsystems

- add DUMMY-define in case the subsystem is enabled but not available (filesystem/misc/locale)
- add missing PSP/VITA-filesystem defines
- sync the order of filesystems in SDL_config.h.cmake/in
- add option to disable locale subsystem in configure

CMakeLists.txt

@@ -2568,19 +2568,19 @@ if(NOT HAVE_SDL_LOADSO)
   set(SOURCE_FILES ${SOURCE_FILES} ${LOADSO_SOURCES})
 endif()
 if(NOT HAVE_SDL_FILESYSTEM)
-  set(SDL_FILESYSTEM_DISABLED 1)
+  set(SDL_FILESYSTEM_DUMMY 1)
   file(GLOB FILESYSTEM_SOURCES ${SDL2_SOURCE_DIR}/src/filesystem/dummy/*.c)
   set(SOURCE_FILES ${SOURCE_FILES} ${FILESYSTEM_SOURCES})
 endif()
 if(NOT HAVE_SDL_LOCALE)
-  set(SDL_LOCALE_DISABLED 1)
+  set(SDL_LOCALE_DUMMY 1)
   file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/locale/dummy/*.c)
   set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
 endif()
 if(NOT HAVE_SDL_MISC)
-  set(SDL_MISC_DISABLED 1)
-  file(GLOB LOCALE_SOURCES ${SDL2_SOURCE_DIR}/src/misc/dummy/*.c)
-  set(SOURCE_FILES ${SOURCE_FILES} ${LOCALE_SOURCES})
+  set(SDL_MISC_DUMMY 1)
+  file(GLOB MISC_SOURCES ${SDL2_SOURCE_DIR}/src/misc/dummy/*.c)
+  set(SOURCE_FILES ${SOURCE_FILES} ${MISC_SOURCES})
 endif()
 
 # We always need to have threads and timers around