Blocks, functions, and methods now have the same code for handling
their bodies.
This means that single-line methods work like single-line functions:
they return the result of their expression.
Instead of an instruction that always instantiates an instance,
the "new" is compiled to a method call on the class, followed by a
method call on the (presumably) new instance.
The former lets built-in types like Fn do special stuff instead of
allocating an instance. In particular, it means:
new Fn { ... }
can just return the block argument.
Bob Nystrom