Unnecessary root-level `and` patterns

[jackfirth]

Encountered here:

#lang resyntax/test

test: "root-level and pattern can be removed when matching on a variable"
--------------------
#lang racket
(define (f xs)
  (match xs
    [(and foo (list x y ...))
     (cons x (reverse foo))]))
--------------------
--------------------
#lang racket
(define (f xs)
  (match xs
    [(list x y ...)
     (cons x (reverse xs))]))
--------------------

This applies whenever match is used on a variable and has an and pattern with an identifier as the outermost pattern in any branch.