PorcE cannot provide good quality Orc level backtraces

[arthurp]

The current PorcE code semantically correctly handles exception, however the print out does not include an Orc backtrace (only the Java stack trace, which is displayed in place of the Orc trace).

PorcE has much of the information needed for this. However, some of it will need to be extracted from the Truffle stack which is someone complex. An intermediate step could be just including only the call site from Orc. This would be much easier.

[arthurp]

This commit is partially addressed in 2dee4d6. However the traces are very bad due to optimization and lack of information from scheduled calls. Some more work will be needed to provide optional good quality stack traces.