SIGSEGV in C2 Node::unique_ctrl_out on 11.0.4

[Roland Westrelin]

Hi Vitaly,

>  So I believe I have a minimal replay that crashes in fastdebug for the
> same reason as product build.  There's a tarball at
> https://www.astron.com/pri/jvm_sigsegv-20191017.tar.gz, which contains a
> "replayer.sh" and a few scala jars (the crashes we're seeing are when
> compiling scala generated bytecodes, as mentioned before.  The bash script
> is pointing at a fastdebug jdk I had locally, but you can of course point
> it to your own (I took Aleksey's fastdebug builds off his site).

Thanks for taking the time to put a reproducer together. I get:

#  assert((Opcode() != Op_If && Opcode() != Op_RangeCheck) || outcnt() == 2) failed: bad if #1

I filed https://bugs.openjdk.java.net/browse/JDK-8232539

Roland.