Define SDL_PLATFORM_* macros instead of underscored ones (#8875)

test/testdraw.c

@@ -12,17 +12,17 @@
 
 /* Simple program:  draw as many random objects on the screen as possible */
 
-#include <stdlib.h>
-#include <time.h>
-
-#ifdef __EMSCRIPTEN__
-#include <emscripten/emscripten.h>
-#endif
-
 #include <SDL3/SDL.h>
 #include <SDL3/SDL_main.h>
 #include <SDL3/SDL_test_common.h>
 
+#ifdef SDL_PLATFORM_EMSCRIPTEN
+#include <emscripten/emscripten.h>
+#endif
+
+#include <stdlib.h>
+#include <time.h>
+
 #define NUM_OBJECTS 100
 
 static SDLTest_CommonState *state;
@@ -200,7 +200,7 @@ static void loop(void)
 
         SDL_RenderPresent(renderer);
     }
-#ifdef __EMSCRIPTEN__
+#ifdef SDL_PLATFORM_EMSCRIPTEN
     if (done) {
         emscripten_cancel_main_loop();
     }
@@ -300,7 +300,7 @@ int main(int argc, char *argv[])
     next_fps_check = SDL_GetTicks() + fps_check_delay;
     done = 0;
 
-#ifdef __EMSCRIPTEN__
+#ifdef SDL_PLATFORM_EMSCRIPTEN
     emscripten_set_main_loop(loop, 0, 1);
 #else
     while (!done) {