[clang] [llvm] [clang][LLVM Demangler] Add a diagnostic that validates that all mang… (PR #111391)

[Erich Keane via llvm-commits]

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@@ -41,7 +41,9 @@
 #include "clang/Basic/CharInfo.h"
 #include "clang/Basic/CodeGenOptions.h"
 #include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/DiagnosticFrontend.h"
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erichkeane wrote:

This is a LOT of include additions.  Could we instead create a function "elsewhere" (new .cpp file perhaps?) that does all the work, perhaps just `CodeGenModule::DiagDemanglerFailures`?

https://github.com/llvm/llvm-project/pull/111391