Omit tables/actions with @hidden from p4runtime

[antoninbas]

No description provided.

[sethfowler]

Looks good to me.

There is one issue: by filtering at this stage, objects which are tagged with @hidden are still considered when generating aliases. If your program has two objects, a.b.c and @hidden d.b.c, ideally a.b.c would receive the alias c. With this patch, it will receive the alias a.b.c, as it would if d.b.c was included in the program.

I don't think this is important enough to block landing this patch, but if you don't have time to fix it now, could you please file an issue about it so we'll remember to fix it at some point?

[antoninbas]

I opened #479. I think this becomes important if the P4 programmer becomes using @hidden. Until then, we only use it for compiler-generated objects and this issue is unlikely to arise.