swift234

API Notes: yaml-to-binary: fix nullability mapping inconsistencies.

We choose not to model "OptionalTypeAdjustment(1, OTK_Optional)" in yaml, so update the known methods to use what we can model.

Introduce the absence of nullability info and use it to set NullabilityAudited and NumAdjustedNullable. (Maybe, after the .def file is gone and we have more testing, we could change the KnownObjCMethod API to better reflect the yaml format..)

Swift SVN r20367