[Bug lto/87906] [9 Regression] ICE in tree check: expected block, have function_decl in block_ultimate_origin, at tree.c:12326 since r264734

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87906

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Better test-cases that do not violate ODR:

$ cat 1.ii
namespace com {
namespace sun {
namespace star {}
} // namespace sun
} // namespace com
namespace a = com::sun::star;
namespace com {
namespace sun {
namespace star {
namespace uno {
class a {
public:
  ~a();
};

class b {
public:
  ~b();
  a c;
};
class c {
  b e;
};
class RuntimeException : b {};
} // namespace uno
} // namespace star
} // namespace sun
} // namespace com
template <typename> void d(int) { throw a::uno::RuntimeException(); }
int f;
void g() { d<a::uno::b>(f); }

$ cat 2.ii
namespace com {
namespace sun {
namespace star {
namespace uno {
class a {
public:
  ~a();
};
class b {
  a c;
};
class RuntimeException : b {};
} // namespace uno
class C : uno::RuntimeException {};
} // namespace star
} // namespace sun
} // namespace com
using com::sun::star::C;
using com::sun::star::uno::RuntimeException;
void d() { throw RuntimeException(); }
void e() { C(); }