SDL: Disable UB sanitizer in signed shift test

SDL Commits
1 
From b77fdcc63882d65e8f70679b99e6026491fac27f Mon Sep 17 00:00:00 2001
From: Anonymous Maarten <[EMAIL REDACTED]>
Date: Thu, 2 Apr 2026 20:13:44 +0200
Subject: [PATCH] Disable UB sanitizer in signed shift test

---
 test/testplatform.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/testplatform.c b/test/testplatform.c
index 9d409d91b8e1f..4e79f6326c122 100644
--- a/test/testplatform.c
+++ b/test/testplatform.c
@@ -208,6 +208,9 @@ static int TST_uallrem(void *a, void *b, int arg, void *result, void *expected)
     return (*(unsigned long long *)result) == (*(unsigned long long *)expected);
 }
 
+#if (defined(__GNUC__) || defined(__clang__)) && !defined(__ICC)
+static int TST_allshl(void *a, void *b, int arg, void *result, void *expected) __attribute__ ((no_sanitize("undefined")));
+#endif
 static int TST_allshl(void *a, void *b, int arg, void *result, void *expected)
 {
     (*(long long *)result) = (*(long long *)a) << arg;