swift234

start teaching sema about didset/willset.  First up, accesses to the
variable are direct in init/destructor and in the didSet/willSet specifiers
themselves (to avoid infinite loops in reassignments).

Also, teach adjustSelfTypeForMember to handle direct accesses properly,
and move isImplicitDirectMemberReference early enough that it can find out
about inferred directness.


Swift SVN r13022