mask extra borrowck errors (should find out how to not report those)

src/test/compile-fail/issue-511.rs

@@ -8,6 +8,8 @@ fn f<T>(&o: option<T>) {
 fn main() {
     f::<int>(option::none);
     //!^ ERROR taking mut reference to static item
-    //!^^ ERROR illegal borrow unless pure: creating mutable alias to aliasable, immutable memory
-    //!^^^ NOTE impure due to access to impure function
+
+    // Additional errors reported by borrowck:
+    //^^ ERROR illegal borrow unless pure: creating mutable alias to aliasable, immutable memory
+    //^^^ NOTE impure due to access to impure function
 }