[Bug lto/65475] [5 Regression] ICE in odr_vtable_hasher::equal (Segmentation fault)

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65475

--- Comment #7 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
The ICE is now fixed. I will leave this open to fix the duplicated ODR warnings
(we probably only want to warn once per type). 

Martin, can you commit the testcase?