Index: test/CodeGenCXX/thinlto-promote-internals.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/thinlto-promote-internals.cpp
@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -triple x86_64-pc-windows-msvc19.0.24215 -emit-llvm \
+// RUN:     -flto=thin -flto-unit -o - %s | FileCheck %s
+
+// CHECK: @"\01??_7B@?A@@6B@" = internal unnamed_addr alias
+// CHECK: define internal %"class.(anonymous namespace)::B"
+
+class A {
+public:
+  virtual int foo() { return 0; }
+};
+
+namespace {
+  class B : public A { };
+}
+
+A *makeA() { return new B(); }
+