swift234

Add special handling of accessibility APIs.

This is a hack that allows us to support accessibility APIs in Swift.
It addresses radar://17509751.

A class might conform to both NSAccessibility (containing accessibility
properties) and individual accessibility protocols (containing
accessibility methods with the same names as the properties). This should
not compile (but currently happens to compile). To avoid the problem down
the road, we import setters and getters instead of the accessibility
properties from NSAccessibility.

Swift SVN r21757