Fix dlang#23166 Set sc3.minst to root module (dlang#23169)

Author: gulugulubing

compiler/src/dmd/semantic3.d

@@ -1860,7 +1860,12 @@ void semanticRTInfo(AggregateDeclaration ad)
     auto sc = ad.rtInfoScope;
     Scope* sc3 = ti.tempdecl._scope.startCTFE();
     sc3.tinst = sc.tinst;
-    sc3.minst = sc.minst;
+    // Use the root module so nested RTInfoImpl instances get codegen'd.
+    // If rtInfoScope comes from a non-root ImportC module whose minst is that
+    // module itself (see scopeCreateGlobal), so needsCodegen() would skip
+    // RTInfoImpl even though TypeInfo references it at link time.
+    // See https://github.com/dlang/dmd/issues/23166.
+    sc3.minst = sc._module.importedFrom;
     if (ad.isDeprecated())
         sc3.stc |= STC.deprecated_;
 

compiler/test/runnable/imports/imp23166.c

@@ -0,0 +1,13 @@
+// Minified from <aws/s3/s3_client.h>
+
+struct MyFoo {
+};
+
+typedef struct MyFoo *(MyFuncPtr)(struct MyFoo *allocator);
+
+struct BrokenStruct {
+    const struct MyFoo *network_interface_names_array;
+    int num_network_interface_names;
+    MyFuncPtr *buffer_pool_factory_fn;
+    void *buffer_pool_user_data;
+};

compiler/test/runnable/test23166.d

@@ -0,0 +1,9 @@
+// https://github.com/dlang/dmd/issues/23166
+
+import imports.imp23166;
+
+void main()
+{
+    auto s = new BrokenStruct();
+    assert(s !is null);
+}