cannot import @agoric/harden under SES-0.7.4 without noTameRegExp

[warner]

The following CJS program:

const { lockdown } = require('ses');
lockdown( { noTameError: true });
require('@agoric/harden'); // fails

when run in an initially-empty directory where I've done yarn add esm ses@0.7.4 @agoric/harden@0.0.4, yields the following error:

$ node -r esm t.js
/tmp/t6/node_modules/@agoric/harden/dist/harden.cjs.js:1
TypeError: RegExp.prototype.source getter called on non-RegExp object
    at Object.get source [as source] (<anonymous>)
    at Object.toString (<anonymous>)
    at /tmp/t6/node_modules/@agoric/harden/dist/harden.cjs.js:280:47
    at Array.forEach (<anonymous>)
    at getAnonIntrinsics (/tmp/t6/node_modules/@agoric/harden/dist/harden.cjs.js:266:20)
    at buildTable (/tmp/t6/node_modules/@agoric/harden/dist/harden.cjs.js:1410:22)
    at Object.<anonymous> (/tmp/t6/node_modules/@agoric/harden/dist/harden.cjs.js:1430:22)
    at Object.<anonymous> (/tmp/t6/node_modules/@agoric/harden/dist/harden.cjs.js:1)

The line in question (harden.cjs.js line 280) is trying to toString an undeniable:

  const undeniableTuples = [
    ['Object.prototype', Object.prototype, {}],
    ['Function.prototype', Function.prototype, function foo() {}],
    ['Array.prototype', Array.prototype, []],
    ['RegExp.prototype', RegExp.prototype, /x/],
    ['Boolean.prototype', Boolean.prototype, true],
    ['Number.prototype', Number.prototype, 1],
    ['String.prototype', String.prototype, 'x'],
    ['%Generator%', Generator, aStrictGenerator],
    ['%AsyncGenerator%', AsyncGenerator, aStrictAsyncGenerator],
    ['%AsyncFunction%', AsyncFunctionPrototype, aStrictAsyncFunction],
  ];

  undeniableTuples.forEach(tuple => {
    const name = tuple[0];
    const undeniable = tuple[1];
    let start = tuple[2];
    if (start === undefined) {
      return;
    }
    start = Object(start);
    if (undeniable === start) {
      return;
    }
    if (undeniable === getProto(start)) {
      return;
    }
    throw new Error(`Unexpected undeniable: ${undeniable}`);
  });

If I change the ${undeniable} to ${name}, it reveals the unexpected undeniable:

Error: Unexpected undeniable: RegExp.prototype

I'm guessing that our fix for #230 was incomplete somehow, and the check that harden does is confused. There are two problems here: the first triggering this Error, and the second is that the undeniable in question throws a second error when the first one tries to call toString on RegExp.prototype.

[warner]

Oh and of course the problem goes away if I add noTameRegExp: true to the lockdown() options, as you'd expect.

[erights]

Fixed in #243