Merge upstream and sdl3-blitters

CMakeLists.txt

@@ -739,6 +739,7 @@ if(SDL_ASSEMBLY)
     cmake_pop_check_state()
     if(COMPILER_SUPPORTS_SSE4_1)
       set(HAVE_SSE4_1 TRUE)
+      sdl_glob_sources("${SDL3_SOURCE_DIR}/src/video/intrin/SDL_blit_A_sse4_1.c")
     endif()
   endif()
   if(SDL_SSE4_2)
@@ -802,6 +803,7 @@ if(SDL_ASSEMBLY)
         return 0;
       }" COMPILER_SUPPORTS_AVX2)
     cmake_pop_check_state()
+    sdl_glob_sources("${SDL3_SOURCE_DIR}/src/video/intrin/SDL_blit_A_*.c")
     if(COMPILER_SUPPORTS_AVX2)
       set(HAVE_AVX2 TRUE)
     endif()