Fix `$crate`-related regressions.

src/librustc_resolve/lib.rs

@@ -845,6 +845,10 @@ fn is_trait(&self) -> bool {
             _ => false,
         }
     }
+
+    fn is_local(&self) -> bool {
+        self.normal_ancestor_id.is_some()
+    }
 }
 
 impl<'a> fmt::Debug for ModuleS<'a> {
@@ -1585,8 +1589,7 @@ fn resolve_module_prefix(&mut self, module_path: &[Ident], span: Option<Span>)
                 ctxt = ctxt.source().0;
             }
             let module = self.invocations[&ctxt.source().1].module.get();
-            let crate_root =
-                if module.def_id().unwrap().is_local() { self.graph_root } else { module };
+            let crate_root = if module.is_local() { self.graph_root } else { module };
             return Success(PrefixFound(crate_root, 1))
         }
 
@@ -2569,7 +2572,8 @@ fn resolve_path(&mut self, id: NodeId, path: &Path, path_depth: usize, namespace
         let unqualified_def = resolve_identifier_with_fallback(self, None);
         let qualified_binding = self.resolve_module_relative_path(span, segments, namespace);
         match (qualified_binding, unqualified_def) {
-            (Ok(binding), Some(ref ud)) if binding.def() == ud.def => {
+            (Ok(binding), Some(ref ud)) if binding.def() == ud.def &&
+                                           segments[0].identifier.name.as_str() != "$crate" => {
                 self.session
                     .add_lint(lint::builtin::UNUSED_QUALIFICATIONS,
                               id,

src/test/compile-fail/lint-qualification.rs

@@ -18,4 +18,11 @@ fn main() {
     use foo::bar;
     foo::bar(); //~ ERROR: unnecessary qualification
     bar();
+
+    let _ = || -> Result<(), ()> { try!(Ok(())); Ok(()) }; // issue #37345
+
+    macro_rules! m {
+        () => { $crate::foo::bar(); }
+    }
+    m!(); // issue #37357
 }