rustdoc: Rename impldoc.for_ty to self_ty

src/rustdoc/doc.rs

@@ -103,7 +103,7 @@ enum itemtag {
     brief: option<str>,
     desc: option<str>,
     iface_ty: option<str>,
-    for_ty: option<str>,
+    self_ty: option<str>,
     methods: [methoddoc]
 };
 

src/rustdoc/extract.rs

@@ -291,7 +291,7 @@ fn impldoc_from_impl(
         brief: none,
         desc: none,
         iface_ty: none,
-        for_ty: none,
+        self_ty: none,
         methods: vec::map(methods) {|method|
             {
                 name: method.ident,