Describe the bug
Preact stores references to an element's event handlers inside a _listeners property on the element itself — this gets compiled to just l causing a conflict in case a form element with the same name exists inside a form — leading to this error:

Uncaught
TypeError: t is not a function
    at HTMLFormElement.<anonymous>

To Reproduce

• Create a HTMLFormElement containing one or several HTMLInputElement
• Attach a submit handler to the form (the event handler can contain a simple console.log)
• Give each of the input elements a name and make sure to name one l e.g. <input name="l">
• Use a Chromium browser
• Use the compiled and minified version of Preact

Here's a StackBlitz link where you can test it out.

Expected behavior
When submitting the form, the event handler should be invoked resulting in a log statement in the browser dev tools.

Actual behavior
An error is thrown.

Possible Solution
Consider using a Symbol for the property key storing event handlers on elements.