SDL: SDL_opengles2_khrplatform.h: add cygwin bit missed in commit 2cd5cd2a.

From d4fa4b46346b973014bb54f60f6c8067b03251e7 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sun, 17 May 2026 11:50:10 +0300
Subject: [PATCH] SDL_opengles2_khrplatform.h: add cygwin bit missed in commit
 2cd5cd2a.

---
 include/SDL3/SDL_opengles2_khrplatform.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/SDL3/SDL_opengles2_khrplatform.h b/include/SDL3/SDL_opengles2_khrplatform.h
index 01646449caedc..ce63eee076cc7 100644
--- a/include/SDL3/SDL_opengles2_khrplatform.h
+++ b/include/SDL3/SDL_opengles2_khrplatform.h
@@ -122,6 +122,8 @@
 #if defined(_WIN32) && !defined(_WIN32_WCE) && !defined(__SCITECH_SNAP__)
     /* Win32 but not WinCE */
 #   define KHRONOS_APIENTRY __stdcall
+#elif defined(__CYGWIN__) /* __CYGWIN__ added by SDL */
+#   define KHRONOS_APIENTRY __stdcall
 #else
 #   define KHRONOS_APIENTRY
 #endif