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

[via llvm-commits]

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@@ -421,8 +421,13 @@ bool sys::RemoveFileOnSignal(StringRef Filename, std::string *ErrMsg) {
     return true;
   }
 
-  if (FilesToRemove == NULL)
+  if (FilesToRemove == NULL) {
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yronglin wrote:

Hmm, yes, it's may depends on globals destruct order. 

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