Convert old-style for loops to new-style

Most could use the each method, but because of the hack used to
disambiguate old- and new-style loops, some had to use vec::each.

(This hack will go away soon.)

Issue #1619

src/librustsyntax/parse/eval.rs

@@ -13,7 +13,7 @@ type ctx =
 fn eval_crate_directives(cx: ctx, cdirs: [@ast::crate_directive], prefix: str,
                          &view_items: [@ast::view_item],
                          &items: [@ast::item]) {
-    for sub_cdir: @ast::crate_directive in cdirs {
+    for cdirs.each {|sub_cdir|
         eval_crate_directive(cx, sub_cdir, prefix, view_items, items);
     }
 }