Fix to dartbug.com/5170, explictly static library variables now get an appropriate error message.

lib/compiler/implementation/resolver.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.
 
 abstract class TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(TypeAnnotation annotation);
   bool isParameterChecked(Element element);
 }
@@ skipping 295 matching lines @@
 
     if (constructor.defaultImplementation === null) {
       // We failed to find a constructor named either
       // "MyInterface.name" or "MyClass.name".
       error(node,
             MessageKind.CANNOT_FIND_CONSTRUCTOR2,
             [name, defaultClass.name]);
     }
   }
 
-  TreeElements resolveField(Element element) {
+  TreeElements resolveField(VariableElement element) {
     Node tree = element.parseNode(compiler);
+    if(element.modifiers.isStatic() && element.variables.isTopLevel()) {
+      error(element.modifiers.getStatic(), MessageKind.TOP_LEVEL_VARIABLE_DECLARED_STATIC);
+    }
     ResolverVisitor visitor = new ResolverVisitor(compiler, element);
     initializerDo(tree, visitor.visit);
     return visitor.mapping;
   }
 
   TreeElements resolveParameter(Element element) {
     Node tree = element.parseNode(compiler);
     ResolverVisitor visitor =
         new ResolverVisitor(compiler, element.enclosingElement);
     initializerDo(tree, visitor.visit);
@@ skipping 2811 matching lines @@
     return result;
   }
   Element lookup(SourceString name) => localLookup(name);
   Element lexicalLookup(SourceString name) => localLookup(name);
 
   Element add(Element newElement) {
     throw "Cannot add an element in a patch library scope";
   }
   String toString() => 'PatchLibraryScope($origin,$patch)';
 }