[clang] [clang][modules] Fix std::initializer_list recognition if it's exported out of a module (PR #118537)

[Chuanqi Xu via cfe-commits]

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@@ -0,0 +1,39 @@
+// RUN: rm -rf %t
+// RUN: mkdir -p %t
+// RUN: split-file %s %t
+//
+// RUN: %clang_cc1 -std=c++20 %t/std.cppm -emit-module-interface -o %t/std.pcm
+// RUN: %clang_cc1 -std=c++20 %t/mod.cppm -fprebuilt-module-path=%t -emit-module-interface -o %t/mod.pcm
+// RUN: %clang_cc1 -std=c++20 -fprebuilt-module-path=%t -verify %t/main.cpp
+
+//--- std.cppm
+export module std;
+
+extern "C++" {
+  namespace std {
+  export template <class E>
+  class initializer_list {
+    const E* _1;
+    const E* _2;
+  };
+  }
+}
+
+//--- mod.cppm
+export module mod;
+
+import std;
+
+export struct A {
+  void func(std::initializer_list<int>) {}
+};
+
+//--- main.cpp
+// expected-no-diagnostics
+import std;
+import mod;
+
+int main() {
+  A{}.func({1,1});
+  return 0;
+}
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ChuanqiXu9 wrote:

nit: new line

https://github.com/llvm/llvm-project/pull/118537