Command to jump to top of closest function or closest non-arrow function

[brettz9]

For larger functions/methods, it'd be very useful to be able to jump to the top of the current function.

For an additional variant of this feature, it'd be great to be able to go to the top of the closest containing function which is not an arrow function, e.g., so as to be able to introspect on what object this deep in some nested arrow functions is referring to.