Add minimal reroducer for the crash after changing deserialization order

Author: dmpolukhin

clang/test/Headers/crash-instantiated-in-scope-cxx-modules2.cpp

@@ -0,0 +1,31 @@
+// RUN: rm -fR %t
+// RUN: split-file %s %t
+// RUN: cd %t
+// RUN: %clang_cc1 -std=c++20 -emit-header-unit -xc++-user-header header.h
+// RUN: %clang_cc1 -std=c++20 -fmodule-file=header.pcm main.cpp
+
+//--- header.h
+template <typename T>
+void f(T) {}
+
+class A {
+  virtual ~A();
+};
+
+inline A::~A() {
+  f([](){});
+}
+
+struct B {
+  void g() {
+    f([](){
+      [](){};
+    });
+  }
+};
+
+// expected-no-diagnostics
+
+//--- main.cpp
+import "header.h";
+// expected-no-diagnostics