Revert "Implement pattern ranges for all numeric types."

This reverts commit ce0f054f9d.

src/comp/syntax/fold.rs

@@ -291,7 +291,6 @@ fn noop_fold_pat(p: pat_, fld: ast_fold) -> pat_ {
           }
           pat_tup(elts) { pat_tup(vec::map(fld.fold_pat, elts)) }
           pat_box(inner) { pat_box(fld.fold_pat(inner)) }
-          pat_range(_, _) { p }
         };
 }