swift234

Bugfixes for the new addressor kinds.

Permit non-Ordinary accesses on references to functions,
with the semantics of devirtualizing the call if the
function is a class member.  This is important for
constructing direct call to addressors from synthesized
materializeForSet accessors: for one, it's more
performant, and for another, addressors do not currently
appear in v-tables.

Synthesize trivial accessors for addressed class members.
We weren't doing this at all before, and I'm still not
sure we're doing it right in all cases.  This is a mess.

Assorted other fixes.  The new addressor kinds seem
to work now.

Swift SVN r24393