[clang] [clang] Add tests for some of CWG issues resolved in Croydon (2026-03) (PR #189299)

[Corentin Jabot via cfe-commits]

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@@ -18,6 +18,25 @@
 #endif
 
 namespace std {
+#if __cplusplus >= 201103L
+using size_t = decltype(sizeof(0));
+template <typename T>
+struct initializer_list {
+  const T *p;
+  size_t n;
+
+  #if __cplusplus >= 201402L
+  constexpr
+  #endif
+  initializer_list(const T *p, size_t n);
+
+  #if __cplusplus >= 201402L
+  constexpr
+  #endif
+  const T* begin() const { return {}; };
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cor3ntin wrote:

do you mean to return p?

https://github.com/llvm/llvm-project/pull/189299