SDL: Disable the Mingw C runtime by default

From 1f177be1e45f54c05125574cb7f94530a53b0726 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sat, 20 Jan 2024 20:53:27 -0800
Subject: [PATCH] Disable the Mingw C runtime by default

Mingw seems to have a bad pow implementation in the C runtime:
'Pow(-72.300000,12.000000), expected [20401381050275984310272.000000], got 20401381050275996893184.000000': Failed
---
 CMakeLists.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8c2af335565e..a9af7ad18e5d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -154,6 +154,9 @@ endif()
 set(SDL_LIBC_DEFAULT ON)
 set(SDL_SYSTEM_ICONV_DEFAULT ON)
 if(WINDOWS)
+  if(MINGW)
+    set(SDL_LIBC_DEFAULT OFF)
+  endif()
   set(SDL_SYSTEM_ICONV_DEFAULT OFF)
 endif()