[clang] [clang] Implement a bitwise_copyable builtin type trait. (PR #86512)

[Sam McCall via cfe-commits]

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@@ -526,6 +526,7 @@ TYPE_TRAIT_2(__is_layout_compatible, IsLayoutCompatible, KEYCXX)
 #include "clang/Basic/TransformTypeTraits.def"
 
 // Clang-only C++ Type Traits
+TYPE_TRAIT_1(__is_bitwise_copyable, IsBitwiseCopyable, KEYCXX)
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sam-mccall wrote:

naming thought #2:

I'm a little concerned that all other type traits that mention "copy" use it to mean "is equivalent to the language-level copy", not "the copy is physically possible".

For that reason I would consider e.g. `__is_bitwise_cloneable`.

https://github.com/llvm/llvm-project/pull/86512