Update comments in cast-lt.pp

Author: harpocrates

src/test/pretty/cast-lt.pp

@@ -4,7 +4,7 @@
 use std::prelude::v1::*;
 #[macro_use]
 extern crate std as std;
-// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -18,8 +18,6 @@
 // pretty-mode:expanded
 // pp-exact:cast-lt.pp
 
-// #4264 fixed-length vector types
-
 macro_rules! negative(( $ e : expr ) => { $ e < 0 });
 
 fn main() { (1 as i32) < 0; }