[clang] [clang] Strict aliasing warning ala GCC [PR50066] (PR #74155)

[Nathan Sidwell via cfe-commits]

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@@ -128,6 +128,10 @@ class DiagnosticOptions : public RefCountedBase<DiagnosticOptions>{
   /// whether -Wsystem-headers is enabled on a per-module basis.
   std::vector<std::string> SystemHeaderWarningsModules;
 
+  /// Level of scrutiny reinterpret_casts get for type-unsafe aliasing
+  /// checks. Requires an ASTConsumer that provides TBAA information.
+  unsigned StrictAliasing;
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urnathan wrote:

I was misled by the -Wundef-prefix pattern that I followed.  Should have looked closer and found the DiagnosticOptions.def file.

https://github.com/llvm/llvm-project/pull/74155