Kernel reentrancy on fake-chain

[michaelfig]

It appears that when the fake chain is run with no delay, we have newly-introduced contention between the simulation timeout and the deliver. We should eliminate this with a simulateBlock input queue.

SwingSet: kernel: We're currently already running at Error <Object <[Object: null prototype] {}>>: here
    at processQueueMessage (/SwingSet/kernel/packages/SwingSet/src/kernel/kernel.js:452:31)
    at Object.run (/SwingSet/kernel/packages/SwingSet/src/kernel/kernel.js:846:15)
    at async deliverInbound (/Users/michael/agoric/agoric-sdk/packages/cosmic-swingset/lib/launch-chain.js:107:5)
fake-chain: error fake processing Error <Object <[Object: null prototype] {}>>: Kernel reentrancy is forbidden
    at processQueueMessage (/SwingSet/kernel/packages/SwingSet/src/kernel/kernel.js:448:15)
    at Object.run (/SwingSet/kernel/packages/SwingSet/src/kernel/kernel.js:846:15)
    at Object.run (/Users/michael/agoric/agoric-sdk/packages/SwingSet/src/controller.js:350:21)
    at deliverInbound (/Users/michael/agoric/agoric-sdk/packages/cosmic-swingset/lib/launch-chain.js:107:22)
    at kernelPerformAction (/Users/michael/agoric/agoric-sdk/packages/cosmic-swingset/lib/block-manager.js:31:13)
    at blockManager (/Users/michael/agoric/agoric-sdk/packages/cosmic-swingset/lib/block-manager.js:95:13)
    at simulateBlock (/Users/michael/agoric/agoric-sdk/packages/cosmic-swingset/lib/ag-solo/fake-chain.js:74:15)
    at async Object.deliver [as deliverator] (/Users/michael/agoric/agoric-sdk/packages/cosmic-swingset/lib/ag-solo/fake-chain.js:109:7)