Remove resolve's xray infrastructure

Since the removal of privacy from resolve, this flag is no longer necessary to
get the test runner working. All of the privacy checks are bypassed by a special
item attribute in the privacy visitor.

Closes #4947

src/librustc/middle/resolve.rs

@@ -25,7 +25,6 @@ use syntax::ast::*;
 use syntax::ast;
 use syntax::ast_util::{def_id_of_def, local_def, mtwt_resolve};
 use syntax::ast_util::{path_to_ident, walk_pat, trait_method_to_ty_method};
-use syntax::attr;
 use syntax::parse::token;
 use syntax::parse::token::{ident_interner, interner_get};
 use syntax::parse::token::special_idents;
@@ -254,19 +253,6 @@ enum MethodSort {
     Provided(NodeId)
 }
 
-// The X-ray flag indicates that a context has the X-ray privilege, which
-// allows it to reference private names. Currently, this is used for the test
-// runner.
-//
-// FIXME #4947: The X-ray flag is kind of questionable in the first
-// place. It might be better to introduce an expr_xray_path instead.
-
-#[deriving(Eq)]
-enum XrayFlag {
-    NoXray,     //< Private items cannot be accessed.
-    Xray        //< Private items can be accessed.
-}
-
 enum UseLexicalScopeFlag {
     DontUseLexicalScope,
     UseLexicalScope
@@ -831,7 +817,6 @@ fn Resolver(session: Session,
         type_ribs: @mut ~[],
         label_ribs: @mut ~[],
 
-        xray_context: NoXray,
         current_trait_refs: None,
 
         self_ident: special_idents::self_,
@@ -883,10 +868,6 @@ struct Resolver {
     // The current set of local scopes, for labels.
     label_ribs: @mut ~[@Rib],
 
-    // Whether the current context is an X-ray context. An X-ray context is
-    // allowed to access private names of any module.
-    xray_context: XrayFlag,
-
     // The trait that the current context can refer to.
     current_trait_refs: Option<~[DefId]>,
 
@@ -3545,13 +3526,6 @@ impl Resolver {
         debug!("(resolving item) resolving {}",
                self.session.str_of(item.ident));
 
-        // Items with the !resolve_unexported attribute are X-ray contexts.
-        // This is used to allow the test runner to run unexported tests.
-        let orig_xray_flag = self.xray_context;
-        if attr::contains_name(item.attrs, "!resolve_unexported") {
-            self.xray_context = Xray;
-        }
-
         match item.node {
 
             // enum item: resolve all the variants' discrs,
@@ -3715,8 +3689,6 @@ impl Resolver {
             fail!("item macros unimplemented")
           }
         }
-
-        self.xray_context = orig_xray_flag;
     }
 
     fn with_type_parameter_rib(&mut self,