[Bug lto/88130] [9 Regression] ICE in copy_function_or_variable, at lto-streamer-out.c:2315 since r260963

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88130

--- Comment #4 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
Created attachment 45282
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45282&action=edit
patch I am testing

This seems like ages old isse where at compile time we decide to not ship the
vtable constructor (because we do not optimize) and at WPA time we think it may
be good idea to stream it. This is done in lto-cgraph and we can't use
optimization level there because variables have no optimize attribute and we do
not know if there is code that is going to be devirtualized (well, we could
probably track this info by tracking all symbols that go into partition but I
doubt it is worth the effort)

ctor_useable_for_folding is not considering case that the constructor is not in
the stream which is fixed here.