Exception transparency

[maurizio cimadamore]

> But due to a previously unreported compiler bug (I'm using javac version
> 1.6.0_07), it won't compile anyway.  I'll be surprised if anyone can find
> production code that compiles today and would break under a hypothetical
> change to lub() for all type parameters that extend Throwable or a subtype.
>    
The program I posted earlier in this thread compiles correctly under jdk 
6 and would fail with the proposed extension of dropping lub() in favor 
of disjunctive types for type-variables extending Throwable. It's 
clearly not production code, but it's something.

Maurizio