[llvm] [Support] Fix memory leak induced by `sys::RemoveFileOnSignal` (PR #159984)

[Alexandre Ganea via llvm-commits]

https://github.com/aganea created https://github.com/llvm/llvm-project/pull/159984

Before this PR, `FilesToRemove` was constructed but never deleted.

>From 6778477f3aa51fefa54e21c6e3f699ddd3405d3c Mon Sep 17 00:00:00 2001
From: Alexandre Ganea <alex_toresh at yahoo.fr>
Date: Sun, 21 Sep 2025 11:12:48 -0400
Subject: [PATCH] [Support] Fix memory leak induced by
 `sys::RemoveFileOnSignal`

Before this PR, `FilesToRemove` was constructed but never deleted.
---
 llvm/lib/Support/Windows/Signals.inc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Support/Windows/Signals.inc b/llvm/lib/Support/Windows/Signals.inc
index dad0fa3066868..db6d2eeb4169c 100644
--- a/llvm/lib/Support/Windows/Signals.inc
+++ b/llvm/lib/Support/Windows/Signals.inc
@@ -421,8 +421,13 @@ bool sys::RemoveFileOnSignal(StringRef Filename, std::string *ErrMsg) {
     return true;
   }
 
-  if (FilesToRemove == NULL)
+  if (FilesToRemove == NULL) {
     FilesToRemove = new std::vector<std::string>;
+    std::atexit([]() {
+      delete FilesToRemove;
+      FilesToRemove = NULL;
+    });
+  }
 
   FilesToRemove->push_back(std::string(Filename));