SDL_image: CMake: defines PNG_USES_IMAGEIO and JPG_USES_IMAGEIO, same as in 'configure'

SDL Commits
1 
From 75d0709eb4ec5403735f56adb6284f662896ffb3 Mon Sep 17 00:00:00 2001
From: Sylvain Becker <[EMAIL REDACTED]>
Date: Thu, 24 Nov 2022 15:55:57 +0100
Subject: [PATCH] CMake: defines PNG_USES_IMAGEIO and JPG_USES_IMAGEIO, same as
 in 'configure' so that you can Enable IMAGE_IO backend, Enable PNG without
 requiring png.h headers

---
 CMakeLists.txt | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 314267fb..802a79a6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -306,6 +306,13 @@ if(APPLE)
         target_sources(SDL2_image PRIVATE
             IMG_ImageIO.m
         )
+
+        if (SDL2IMAGE_PNG)
+            target_compile_definitions(SDL2_image PRIVATE PNG_USES_IMAGEIO)
+        endif()
+        if (SDL2IMAGE_JPG)
+            target_compile_definitions(SDL2_image PRIVATE JPG_USES_IMAGEIO)
+        endif()
     else()
         target_compile_definitions(SDL2_image PRIVATE SDL_IMAGE_USE_COMMON_BACKEND)
     endif()