Tag build swift-DEVELOPMENT-SNAPSHOT-2016-11-15-a
Merge remote-tracking branch 'origin/swift-3.1-branch' into stable

* origin/swift-3.1-branch:
  Don't require nullability on 'va_list', even when it's a pointer.
  Don't require nullability on 'va_list' harder.
  [APINotes] Add support for nullability on arrays.
  Don't require nullability on 'va_list'.
  Warn when 'assume_nonnull' infers nullability within an array.
  Add -Wnullability-completeness-on-arrays.
  Accept nullability qualifiers on array parameters.
  Don't require nullability on template parameters in typedefs.