function recursivelyRemoveStartAndEnd(o) {
    if (Array.isArray(o)) {
        o.forEach(recursivelyRemoveStartAndEnd);
        return;
    }
    if (o && typeof o === "object") {
        delete o.start;
        delete o.end;
        Object.keys(o).filter(key => key !== "loc").forEach(key => {
            recursivelyRemoveStartAndEnd(o[key]);
        });
    }
}
acorn adds these "start" and "end" properties
which we don't officially support, we remove
them before creating our test fixtures
@param {StartEnd[]} o The array or object to modify
@returns {void}