rustc: Fix a dynamic borrow error in resolve

Closes #8208
Closes #10980

Author: alexcrichton

src/librustc/middle/resolve.rs

@@ -2040,7 +2040,7 @@ impl<'a> Resolver<'a> {
             return;
         }
 
-        let mut imports = module.imports.borrow_mut();
+        let imports = module.imports.borrow();
         let import_count = imports.len();
         while module.resolved_import_count.get() < import_count {
             let import_index = module.resolved_import_count.get();

src/test/compile-fail/issue-8208.rs

@@ -0,0 +1,17 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(globs)]
+
+use self::*; //~ ERROR: unresolved import
+
+fn main() {
+}
+