Fix null.runtimeType, reflect(null).type.superinterfaces, and reflect(null).getField.

sdk/lib/_internal/compiler/implementation/resolution/members.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of resolution;
 
 abstract class TreeElements {
   Element get currentElement;
   Setlet<Node> get superUses;
 
@@ skipping 785 matching lines @@
       if (element.isPatched) {
         // Ensure handling patch after origin.
         element.patch.ensureResolved(compiler);
       }
     } else { // Handle patch classes:
       element.resolutionState = STATE_STARTED;
       // Ensure handling origin before patch.
       element.origin.ensureResolved(compiler);
       // Ensure that the type is computed.
       element.computeType(compiler);
-      // Copy class hiearchy from origin.
+      // Copy class hierarchy from origin.
       element.supertype = element.origin.supertype;
       element.interfaces = element.origin.interfaces;
       element.allSupertypesAndSelf = element.origin.allSupertypesAndSelf;
       // Stepwise assignment to ensure invariant.
       element.supertypeLoadState = STATE_STARTED;
       element.supertypeLoadState = STATE_DONE;
       element.resolutionState = STATE_DONE;
       // TODO(johnniwinther): Check matching type variables and
       // empty extends/implements clauses.
     }
@@ skipping 3716 matching lines @@
     return finishConstructorReference(visit(expression),
                                       expression, expression);
   }
 }
 
 /// Looks up [name] in [scope] and unwraps the result.
 Element lookupInScope(Compiler compiler, Node node,
                       Scope scope, String name) {
   return Elements.unwrap(scope.lookup(name), compiler, node);
 }