[clang] [SystemZ] Do not run mbackchain-4.c test without SystemZ target (PR #71678)

[Ilya Leoshkevich via cfe-commits]

https://github.com/iii-i created https://github.com/llvm/llvm-project/pull/71678

mbackchain-4.c requires running the backend and causes CI failures when this target is not configured.

>From 284f2d4f844a03ece42eb6dbe7c0d889cf1b01e4 Mon Sep 17 00:00:00 2001
From: Ilya Leoshkevich <iii at linux.ibm.com>
Date: Wed, 8 Nov 2023 15:16:51 +0100
Subject: [PATCH] [SystemZ] Do not run mbackchain-4.c test without SystemZ
 target

mbackchain-4.c requires running the backend and causes CI failures when
this target is not configured.
---
 clang/test/CodeGen/SystemZ/mbackchain-4.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clang/test/CodeGen/SystemZ/mbackchain-4.c b/clang/test/CodeGen/SystemZ/mbackchain-4.c
index 6e5f4fc5da40084..43f25137fffa51c 100644
--- a/clang/test/CodeGen/SystemZ/mbackchain-4.c
+++ b/clang/test/CodeGen/SystemZ/mbackchain-4.c
@@ -1,3 +1,4 @@
+// REQUIRES: systemz-registered-target
 // RUN: %clang --target=s390x-linux -O1 -S -o - %s | FileCheck %s
 
 __attribute__((target("backchain")))