This is the last piece of Clayton's #26179 to be implemented with file tags.
All diffs are accounted for. Followup will use this to streamline some
packages.
Also add some V(5) debugging - it was helpful in diagnosing various issues, it
may be helpful again.
This drives most of the logic of deep-copy generation from tags like:
// +deepcopy-gen=package
..rather than hardcoded lists of packages. This will make it possible to
subsequently generate code ONLY for packages that need it *right now*, rather
than all of them always.
Also remove pkgs that really do not need deep-copies (no symbols used
anywhere).
In bringing back Clayton's PR piece-by-piece this was almost as easy to
implement as his version, and is much more like what I think we should be
doing.
Specifically, any time which defines a .DeepCopy() method will have that method
called preferentially. Otherwise we generate our own functions for
deep-copying. This affected exactly one type - resource.Quantity. In applying
this heuristic, several places in the generated code were simplified.
To achieve this I had to convert types.Type.Methods from a slice to a map,
which seems correct anyway (to do by-name lookups).
This re-institutes some of the rolled-back logic from previous commits. It
bounds the scope of what the deepcopy generator is willing to do with regards
to generating and calling generated functions.
