cmake: only use precompile headers for C and CXX

CMakeLists.txt

@@ -3126,6 +3126,9 @@ if(APPLE)
     if(FILE_EXTENSION STREQUAL ".m")
       set_property(SOURCE ${SOURCE_FILE} APPEND_STRING PROPERTY COMPILE_FLAGS " -x objective-c")
     endif()
+    if(NOT FILE_EXTENSION STREQUAL ".c" AND NOT FILE_EXTENSION STREQUAL ".cpp")
+      set_property(SOURCE ${SOURCE_FILE} PROPERTY SKIP_PRECOMPILE_HEADERS 1)
+    endif()
   endforeach()
 endif()
 
@@ -3254,7 +3257,7 @@ if(SDL_SHARED)
   set_property(TARGET SDL3-shared APPEND PROPERTY COMPATIBLE_INTERFACE_STRING "SDL_VERSION")
   set_property(TARGET SDL3-shared PROPERTY INTERFACE_SDL_VERSION "SDL${SDL3_VERSION_MAJOR}")
   if(NOT CMAKE_VERSION VERSION_LESS "3.16")
-    target_precompile_headers(SDL3-shared PRIVATE "${PROJECT_SOURCE_DIR}/src/SDL_internal.h")
+    target_precompile_headers(SDL3-shared PRIVATE "$<$<OR:$<COMPILE_LANGUAGE:C>,$<COMPILE_LANGUAGE:CXX>>:${PROJECT_SOURCE_DIR}/src/SDL_internal.h>")
   endif()
 endif()
 
@@ -3296,7 +3299,7 @@ if(SDL_STATIC)
   set_property(TARGET SDL3-static APPEND PROPERTY COMPATIBLE_INTERFACE_STRING "SDL_VERSION")
   set_property(TARGET SDL3-static PROPERTY INTERFACE_SDL_VERSION "SDL${SDL3_VERSION_MAJOR}")
   if(NOT CMAKE_VERSION VERSION_LESS "3.16")
-    target_precompile_headers(SDL3-static PRIVATE "${PROJECT_SOURCE_DIR}/src/SDL_internal.h")
+    target_precompile_headers(SDL3-static PRIVATE "$<$<OR:$<COMPILE_LANGUAGE:C>,$<COMPILE_LANGUAGE:CXX>>:${PROJECT_SOURCE_DIR}/src/SDL_internal.h>")
   endif()
 endif()