SDL: Correct default structure packing on Windows ARM64

From a60986caa8206e50b1ea5f8cb4821e40e18c572b Mon Sep 17 00:00:00 2001
From: Cameron Gutman <[EMAIL REDACTED]>
Date: Sun, 27 Mar 2022 19:03:54 -0500
Subject: [PATCH] Correct default structure packing on Windows ARM64

See issue #5454 for details
---
 include/begin_code.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/begin_code.h b/include/begin_code.h
index 63f064b6f8c..b1b1a3a9bea 100644
--- a/include/begin_code.h
+++ b/include/begin_code.h
@@ -107,7 +107,7 @@
 #ifdef __BORLANDC__
 #pragma nopackwarning
 #endif
-#ifdef _M_X64
+#ifdef _WIN64
 /* Use 8-byte alignment on 64-bit architectures, so pointers are aligned */
 #pragma pack(push,8)
 #else