[clang] [Clang] Added explanation why a is trivial copyable evaluated to false. (PR #142341)

[Shamshura Egor via cfe-commits]

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@@ -1922,6 +1924,7 @@ static std::optional<TypeTrait> StdNameToTypeTrait(StringRef Name) {
   return llvm::StringSwitch<std::optional<TypeTrait>>(Name)
       .Case("is_trivially_relocatable",
             TypeTrait::UTT_IsCppTriviallyRelocatable)
+      .Case("is_trivially_copyable", TypeTrait::UTT_IsTriviallyCopyable)
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egorshamshura wrote:

I'm not sure if I did it right, but I couldn't figure out how TYPE_TRAIT_1 could get a name without the "__" prefix. So I made a TYPE_TRAIT_DIAG for this

https://github.com/llvm/llvm-project/pull/142341