Remove pretty-expanded from 2 tests; deriving(Ord) uses unstable intrinsic.

src/test/run-pass/issue-18738.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// pretty-expanded FIXME #23616
-
 #[derive(Eq, PartialEq, PartialOrd, Ord)]
 enum Test<'a> {
     Int(&'a isize),

src/test/run-pass/while-prelude-drop.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// pretty-expanded FIXME #23616
-
 #![feature(collections)]
 
 use std::string::String;