[clang] [clang][Frontend] Batch LangOptions context hashing (PR #203162)

[David Zbarsky via cfe-commits]

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@@ -5215,15 +5215,22 @@ std::string CompilerInvocation::computeContextHash() const {
   HBuilder.add(serialization::VERSION_MAJOR, serialization::VERSION_MINOR);
 
   // Extend the signature with the language options
-  // FIXME: Replace with C++20 `using enum LangOptions::CompatibilityKind`.
-  using CK = LangOptions::CompatibilityKind;
+  const unsigned LanguageOptionValues[] = {
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dzbarsky wrote:

These values come from the current invocation’s LangOpts, so I don't think it can be constexpr?

https://github.com/llvm/llvm-project/pull/203162