Re: [streams] Tidy up precondition checking in ErrorReadableStream (f6d7882)

Generated from code. Sorry it's not about strategy but about underlyingSource. For example,
- CallReadableStreamPull() calls ErrorReadableStream(stream, e) when pullingPromise is rejected. Since the underlyingSource already has the controller so it can do a bad thing that is to call controller.error() and also return a rejected promise. If this happens, we hit the `Assert: stream@[[state]] is "readable"` since controller.error() has already errored the stream.

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