swift234

Implement most of support for properties in function scope, part of rdar://15922884.

Most of the complexity here is teaching SILGen how to handle closed-over direct 
accesses to observing properties, since all of the getter/setter/willSet/didSet
members of the property are actually full closures when in a function body.

We generate correct but really terrible code here, since the setter captures the
willset/didset members themselves.  I'm not worrying about the performance of 
this construct though, functionality is what matters.


Swift SVN r13778