Convert DefId to use DefIndex, which is an index into a list of

paths, and construct paths for all definitions. Also, stop rewriting
DefIds for closures, and instead just load the closure data from
the original def-id, which may be in another crate.

src/librustdoc/html/format.rs

@@ -19,9 +19,8 @@ use std::fmt;
 use std::iter::repeat;
 
 use rustc::metadata::cstore::LOCAL_CRATE;
-use rustc::middle::def_id::DefId;
+use rustc::middle::def_id::{CRATE_DEF_INDEX, DefId};
 use syntax::abi::Abi;
-use syntax::ast;
 use rustc_front::hir;
 
 use clean;
@@ -387,7 +386,7 @@ fn primitive_link(f: &mut fmt::Formatter,
         Some(&cnum) => {
             let path = &m.paths[&DefId {
                 krate: cnum,
-                xxx_node: ast::CRATE_NODE_ID,
+                index: CRATE_DEF_INDEX,
             }];
             let loc = match m.extern_locations[&cnum] {
                 (_, render::Remote(ref s)) => Some(s.to_string()),