Java: Add support for data flow through thrown exceptions.

[aschackmull]

A fresh port of #9914 to present-day main.
I haven't included negative types for now.

[yoff]

This looks good, as far as I can tell.
One thing is that all summaries can now throw, I guess we might want to replace that with a big yml list in the future.
As I understand it, the new CatchParameterNode will be followed in the CFG by CatchTypeTestNode (by the existing CFG rules), which may then end up in a catch, another type test with catch-all type, or an uncaught, with the latter two having exceptional return type.
I suppose we have to redo the performance testing to verify all is well.

[aschackmull]

I suppose we have to redo the performance testing to verify all is well.

All is not well - I know that. So I'm not going to merge this until I have more time to dig into the performance problems.

[aschackmull]

One thing is that all summaries can now throw

Uhm, no?

As I understand it, the new CatchParameterNode will be followed in the CFG by CatchTypeTestNode

No. They're data flow nodes - not CFG nodes, they're not anywhere in the CFG. And the order is the other way round.