ngage: Remove Nokia N-Gage support.

This can be reverted if a toolchain arrives that can handle C99 features like
variables declared in the middle of a scope, but for now we literally can't
compile SDL3 for this platform.

Fixes #11243.

include/SDL3/SDL_main.h

@@ -134,13 +134,6 @@
         */
         #define SDL_MAIN_AVAILABLE
 
-    #elif defined(SDL_PLATFORM_NGAGE)
-        /*
-        TODO: not sure if it should be SDL_MAIN_NEEDED, in SDL2 ngage had a
-                main implementation, but wasn't mentioned in SDL_main.h
-         */
-        #define SDL_MAIN_AVAILABLE
-
     #endif
 #endif /* SDL_MAIN_HANDLED */
 

include/SDL3/SDL_main_impl.h

@@ -131,18 +131,6 @@
 
             /* end of SDL_PLATFORM_WINDOWS impls */
 
-        #elif defined(SDL_PLATFORM_NGAGE)
-            /* same typedef as in ngage SDKs e32def.h */
-            typedef signed int TInt;
-            /* TODO: if it turns out that this only works when built as C++,
-                     move SDL_PLATFORM_NGAGE into the C++ section in SDL_main.h */
-            TInt E32Main()
-            {
-                return SDL_RunApp(0, NULL, SDL_main, NULL);
-            }
-
-            /* end of SDL_PLATFORM_NGAGE impl */
-
         #else /* platforms that use a standard main() and just call SDL_RunApp(), like iOS and 3DS */
             int main(int argc, char *argv[])
             {

include/SDL3/SDL_platform_defines.h

@@ -112,16 +112,6 @@
 #undef SDL_PLATFORM_LINUX
 #endif
 
-#ifdef __NGAGE__
-
-/**
- * A preprocessor macro that is only defined if compiling for Nokia N-Gage.
- *
- * \since This macro is available since SDL 3.1.3.
- */
-#define SDL_PLATFORM_NGAGE 1
-#endif
-
 #if defined(__unix__) || defined(__unix) || defined(unix)
 
 /**