[clang] [clang][amdgpu] getLLVMSyncScopeStr - fix MSVC not all control paths return a value warning. NFC. (PR #180501)

[Simon Pilgrim via cfe-commits]

https://github.com/RKSimon created https://github.com/llvm/llvm-project/pull/180501

None

>From ccfe52ca1689d5bd2b080c9a2a2c37d18bfa30d9 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Mon, 9 Feb 2026 10:32:32 +0000
Subject: [PATCH] [clang][amdgpu] getLLVMSyncScopeStr - fix MSVC not all
 control paths return a value warning. NFC.

---
 clang/lib/CodeGen/Targets/AMDGPU.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clang/lib/CodeGen/Targets/AMDGPU.cpp b/clang/lib/CodeGen/Targets/AMDGPU.cpp
index 27e937b81129d..4ac7f42289d6d 100644
--- a/clang/lib/CodeGen/Targets/AMDGPU.cpp
+++ b/clang/lib/CodeGen/Targets/AMDGPU.cpp
@@ -525,6 +525,7 @@ StringRef AMDGPUTargetCodeGenInfo::getLLVMSyncScopeStr(
   case SyncScope::OpenCLAllSVMDevices:
     return IsOneAs ? "one-as" : "";
   }
+  llvm_unreachable("Unknown SyncScope enum");
 }
 
 void AMDGPUTargetCodeGenInfo::setTargetAtomicMetadata(