empty diagnostic method list from amm public facet etc.

Describe the bug

The “no method” diagnostic from the AMM public facet used to include the list of names of methods that it does have. Now that list is empty.

To Reproduce

In a REPL:

command[10] E(home.agoricNames).lookup('instance', 'amm')
history[10] [Object Alleged: InstanceHandle]{}
command[11] E(home.zoe).getPublicFacet(h[10])
history[11] [Object Alleged: AMM publicFacet]{}
command[12] E(h[11]).help()
history[12] Promise.reject("TypeError: target has no method \"help\", has []")

Expected behavior

The has [] list should include the available methods; for example:

command[13] E(home.zoe).getPublicFacet(E(home.agoricNames).lookup('instance', 'Pegasus'))
history[13] [Object Alleged: pegasus]{}
command[14] E(h[13]).help()
history[14] Promise.reject("TypeError: target has no method \"help\", has [\"getLocalIssuer\",\"makeInvitationToTransfer\",\"makePegasusConnectionKit\"]")

Platform Environment

• what OS are you using? what version of Node.js? v16.17.0
• is there anything special/unusual about your platform?
• what version of the Agoric-SDK are you using? (run git describe --tags --always)

@agoric/vat-data@0.4.3-209-g095c89a29

Additional context

I suspect this is due to wrapping the AMM public facet in virtual / durable API stuff.

cc @michaelfig @Chris-Hibbert @turadg

[dckc]

Good to see that land, but I think this needs an endo update before it’s fixed.

[michaelfig]

The code that displays the diagnostic uses Reflect.ownKeys(obj) to fetch the properties. Very likely with the introduction of Far Classes, method properties are moved somewhere else in the prototype chain (not as “own” properties of the object identity).

@erights, do you care to weigh in on this?