swift234

Import Objective-C properties as Swift variables.

Note that we have to be very careful not to introduce ambiguities
between the name of the getter and the name of the property, so we do
the following:
  - "Informal" properties (where there is no @property) are not
  mapped to Swift variables. The methods are just methods.
  - An @property suppresses name lookup's ability to find
  the getters and setters of that property, so having a "foo" property
  eliminates the "foo" and "setFoo" methods.
  - If an @property is added in a subclass, such that its getter or
  setter come from a superclass, than that property cannot be mapped
  to a Swift variable. Hopefully, this is rare.

As part of this, I had to make sure that Objective-C method overrides
were recorded as overrides in the Swift AST. The same will need to
happen for properties at some point.



Swift SVN r3245