Consider treating nameless forms similar to nameless regions

[joanmarie]

In ARIA 1.1, we added the requirement that authors MUST name their regions. Then, in the Core AAM, we added conditional mappings: Expose as a landmark if it has an explicit name; don't expose as a landmark if it lacks a name.

It has been suggested that we do something similar for the form role. See #514). This issue was closed and moved to Core-AAM for the conditional mappings (w3c/core-aam#11). However, we cannot take steps on that Core-AAM issue until we decide what to do in the ARIA spec itself.

[stevefaulkner]

note this is how its is defined for HTML form element