Compiling this testcase:
---
template<class T>
struct super {
  int Y;
  void foo();
};

template <class T> 
struct test : virtual super<int> {};

extern test<int> X;

void foo() {
  X.foo();
}
---

Causes the C++ frontend to crash like this:

ERROR: Type doesn't have size: "struct.test<int>"
2003-10-27-VirtualBaseClassCrash.cpp: In function `void foo()':
2003-10-27-VirtualBaseClassCrash.cpp:14: internal compiler error: in
llvm_type_get_size, at llvm-types.c:70

I forgot to mention that this is tested by:
test/Regression/C++Frontend/2003-10-27-VirtualBaseClassCrash.cpp

This is now fixed in the C++ front-end.