swift234

[PrintAsObjC] Print ownership qualifiers on properties.

weak => 'weak', unless the type is a CF type. I'm not sure weak references to
        CF types work anyway, but until we have that cleared up this works.

unowned => 'assign'. In Objective-C, use of 'assign' for object properties is
           largely deprecated in favor of 'unsafe_unretained', but unowned
           properties behave more like a 'safe_unretained'. Since they don't
           auto-update like 'weak', though, this should hint to clients to
           be careful about lifetimes.

unowned(unsafe) => 'unsafe_unretained'

As before, Arrays, Dictionaries, and Strings are considered 'copy' properties;
blocks are now considered 'copy' properties as well.

All other types get their (implied)  default: 'strong' for objects, 'assign'
for primitives.

<rdar://problem/17346846>

Swift SVN r20112