Disable more undesired syntax

[rekmarks]

This PR expands the kinds of JavaScript syntax we forbid using the no-restricted-syntax rule to include:

• with statements
  • Because with is very strange and we don't have a use case for it!
• Function expressions
  • Because they're useless and weird! Just use arrow functions.
  • Note that a function expression is of the form const foo = function () { /* do something */ };, and is not to be confused with function declarations, e.g. function bar () { /* do something */ };
• The in operator
  • Because the property lookup walks the prototype chain, wherefore e.g. 'toString' in {} evaluates to true. We should practically always use Reflect.hasOwnProperty instead.

[Gudahtt]

The instanceof operator, except if the right-hand operand is Error

I just thought of another use case for instanceof: custom error classes. e.g. https://github.com/MetaMask/auto-changelog/blob/94354653254e6c616efc9135c600c09961335740/src/cli.ts#L132

[mcmire]

I think if we removed the instanceof rule for now then I would be good with this!

[Gudahtt]

Agreed. Especially with TypeScript v4.4, I expect that instanceof with custom error classes will be a fairly common occurrence.

[rekmarks]

@Gudahtt @mcmire I removed this:

• The instanceof operator, except if the right-hand operand is Error
  • instanceof checks if the prototype of the two operands are the same. We can almost never be assured of this, except for globals like Error. We should just make explicit exceptions for this operator for those rare exceptions.

[mcmire]

Sweet, looks good!

[Gudahtt]

I am in favour of this as well. I can approve after the conflicts are resolved, and once v10 has been published. Better to keep this for the v11 release to avoid making the v10 update too challenging.