[clang] [Clang] Fix assertion failure in SDiagsWriter when finish() is not called (PR #181712)

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@@ -146,7 +146,10 @@ class SDiagsWriter : public DiagnosticConsumer {
     EmitPreamble();
   }
 
-  ~SDiagsWriter() override {}
+  ~SDiagsWriter() override {
+    if (OriginalInstance && !IsFinishing)
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zeyi2 wrote:

I used a RAII approach to ensure blocks are always closed during early exits. I'm not certain if this is the preferred way here. I checked LLVM Coding Standards but didn't find specific guidance regarding RAII safety guards. If Tooling prefers a more explicit cleanup path or has other conventions, I'll refactor this based on your feedback :)

https://github.com/llvm/llvm-project/pull/181712