[lldb][test] Adjust TestTypeList.py on Windows with exceptions

Since llvm#148691 enabled
exceptions when compiling the tests, this test has been failing.

Much like was noted there, one of the variables disappeared
from the debug info. Giving it a non-zero size and initialising
it fixed that.

Author: DavidSpickett

lldb/test/API/python_api/type/main.cpp

@@ -44,7 +44,12 @@ template <unsigned Value> struct PointerInfo {
 };
 
 template <unsigned Value, typename InfoType = PointerInfo<Value>>
-struct Pointer {};
+struct Pointer {
+  // When compiling for Windows with exceptions enabled, this struct
+  // must contain something that takes space and is initialised.
+  // Otherwise it will not be present in the debug information.
+  int pad = 0;
+};
 
 enum EnumType {};
 enum class ScopedEnumType {};