[clang] [clang] Implement CWG3135 - constexpr structured bindings with prvalues from tuples (PR #191880)

[Vlad Serebrennikov via cfe-commits]

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@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -std=c++2c -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++2c -fsyntax-only -verify %s
+
+
+namespace std {
+  using size_t = decltype(sizeof(0));
+  template<typename> struct tuple_size;
+  template<size_t, typename> struct tuple_element;
+}
+
+struct Pinned {
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Endilll wrote:

Part of the test outside of namespace `std` should be wrapped in `namespace cwg3135`, and you need a `// cwg3135 23` comment, like other C++ DR tests have.

https://github.com/llvm/llvm-project/pull/191880