[phobos] Throwing Object

[Sean Kelly]

In a prior discussion with Andrei we agreed that in instances where there are multiple in-flight exceptions, the exceptions would all be chained via the .next property and passed up the stack together.  I just started implementing some of the code for this and have run into a snag: it's possible to throw instances of Object, and Object doesn't have a .next field.  I've toyed with some rather complex rules for resolving this, but the real problem is that Object instances can be thrown at all.  May I assume that the user should only ever throw Exceptions (ie. children of Error or Exception) and have some straightforward way for handling the Object case, be it ignore the Object, wrap it in an ObjectWrapperException, or something like that?