SDL: don't use CMAKE_COMPILER_IS_MINGW

From d9f70878f9fb531c5a9fc7adfa1fda456b77010c Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Wed, 24 Nov 2021 18:10:00 +0300
Subject: [PATCH] don't use CMAKE_COMPILER_IS_MINGW

Fixes https://github.com/libsdl-org/SDL/issues/5002
---
 CMakeLists.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e8963a2976..8a755c6bde 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1519,7 +1519,7 @@ elseif(WINDOWS)
     if(DEFINED MSVC_VERSION AND NOT ${MSVC_VERSION} LESS 1700)
         set(USE_WINSDK_DIRECTX TRUE)
     endif()
-    if(NOT CMAKE_COMPILER_IS_MINGW AND NOT USE_WINSDK_DIRECTX)
+    if(NOT MINGW AND NOT USE_WINSDK_DIRECTX)
       if("$ENV{DXSDK_DIR}" STREQUAL "")
         message_error("DIRECTX requires the \$DXSDK_DIR environment variable to be set")
       endif()
@@ -1537,7 +1537,7 @@ elseif(WINDOWS)
     check_include_file(dxgi.h HAVE_DXGI_H)
     if(HAVE_D3D_H OR HAVE_D3D11_H OR HAVE_DDRAW_H OR HAVE_DSOUND_H OR HAVE_DINPUT_H)
       set(HAVE_DIRECTX TRUE)
-      if(NOT CMAKE_COMPILER_IS_MINGW AND NOT USE_WINSDK_DIRECTX)
+      if(NOT MINGW AND NOT USE_WINSDK_DIRECTX)
       # TODO: change $ENV{DXSDL_DIR} to get the path from the include checks
         target_link_directories(sdl-build-options INTERFACE "$$ENV{DXSDK_DIR}\\lib\\${PROCESSOR_ARCH}")
         target_include_directories(sdl-build-options INTERFACE "$ENV{DXSDK_DIR}\\Include")