ObjectBindingPatterns can't end with multiple commas

test/language/destructuring/binding/syntax/property-list-followed-by-a-single-comma.js

@@ -19,6 +19,4 @@ function fn1({x,}) {}
 
 function fn2({a: {p: q, }, }) {}
 
-function fn3({x,,}) {}
-
-function fn4({x,,,,,,,}) {}
+function fn3({x,}) {}