swift234

[ClangImporter] Don't bridge weak and unsafe_unretained properties.

...to value types. Do continue bridging BOOL to Bool and such.

If the Objective-C API author went out of their way to indicate
ownership, they're probably using the reference semantics for
something. Give them the benefit of the doubt and leave the properties
declared using reference types. (It's not that they wouldn't work
correctly using Any, but that it's obscuring the intended interface.
And any /specific/ bridged value types /might/ actually cause issues
by causing copies.)

There is one wrinkle here involving declarations in the "accessibility
protocols" on Apple platforms, which sometimes use methods and
sometimes properties. The Swift compiler already deals with these by
always importing these as methods, so treat these like any other
methods and use value types when relevant.

rdar://problem/27526957