SDL_net: cmake: Turn off PLATFORM_SUPPORTS_SHARED by default for MS-DOS.

SDL Commits
1 
From 4ffa92ace93ec439f0013f1a36a9c4f30e3cd838 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Sat, 6 Jun 2026 22:47:37 -0400
Subject: [PATCH] cmake: Turn off PLATFORM_SUPPORTS_SHARED by default for
 MS-DOS.

(We can turn this back on for DXEs eventually.)
---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 19d129b..5b89ac9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -67,7 +67,7 @@ include(CMakePackageConfigHelpers)
 include(GNUInstallDirs)
 
 set(PLATFORM_SUPPORTS_SHARED ON)
-if(EMSCRIPTEN OR VITA OR PSP OR PS2 OR N3DS OR RISCOS)
+if(EMSCRIPTEN OR VITA OR PSP OR PS2 OR N3DS OR RISCOS OR DOS)
     set(PLATFORM_SUPPORTS_SHARED OFF)
 endif()