This lets us make it a grammar feature and not a lexer trick.
Newlines are explicitly ignored in some parts of the grammar. This
lets, for example, things like "|" ignore the newline when used as
an operator, but not when used as a parameter delimiter in a block
argument.
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.
They are now invoked like "new Foo".
Also, superclass constructors are now much less semantically
and syntactically weird. Since the instance is created before
any constructor is called, there's no point in time where the
instance isn't there.
