[patch] avoid ICE due to NULL pointer dereference in ipa-comdats.c

[Sebastian Pop]

Jan Hubicka wrote:
> I am bit in hurry, so just quickly (will give it second look at evening).  The
> pass is a simple dataflow propagating preferred sections. NULL means that the
> symbol in question was not visited yet.  Assuming that all symbols are reachable,
> this should not happen by the end of dataflow process (well, thining about it,
> perhaps used attribute can trigger it, but it ought to be handled earlier).
> 
> So I would like to know why the symbols survives remove_unreachable_functions...

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63313

Let me know if you cannot reproduce the ICE.

Thanks,
Sebastian