Crash in CallNode::extract_projections

[Florian Weimer]

* Aleksey Shipilev:

> On 8/25/20 9:49 AM, Florian Weimer wrote:
>> Poking around the core file, the crash happens because
>> pn->unique_ctrl_out() is zero:
>> 
>>          // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
>>          projs->fallthrough_proj = pn;
>>          const Node *cn = pn->unique_ctrl_out();
>>          if (cn->is_Catch()) {
>>            ProjNode *cpn = NULL;
>
> Probably caused by:
>    https://bugs.openjdk.java.net/browse/JDK-8251527
>
> Any simple reproducer?

Not really.  It's a GUI application, and I assume the crash happens
when compiling the AES code for use from HTTPS, so there's also a
networking dependency (over the Internet no less).  And the download
is cached.  So it's not easy to tell whether a build is fine, or
whether the crash has not happened yet.  My attempt at bisecting went
wrong.

I have not seen any crashes yet before JDK-8251527.

I can reproduce it more or less at will, though, so I could do some
testing under guidance?