[llvm] Fix MSVC "not all control paths return a value" warning (PR #169222)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon created https://github.com/llvm/llvm-project/pull/169222

None

>From c08cc62052abc354a5d797f094eb8adea0f3ab30 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Sun, 23 Nov 2025 16:00:41 +0000
Subject: [PATCH] Fix MSVC "not all control paths return a value" warning

---
 llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
index d6d63f3b6198d..baeab6a33ff6a 100644
--- a/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64MachineFunctionInfo.cpp
@@ -183,6 +183,7 @@ bool AArch64FunctionInfo::shouldSignReturnAddress(SignReturnAddress Condition,
   case SignReturnAddress::All:
     return true;
   }
+  llvm_unreachable("Unknown SignReturnAddress enum");
 }
 
 bool AArch64FunctionInfo::shouldSignReturnAddress(