Migrate DDC to the new analysis driver.

pkg/dev_compiler/lib/src/compiler/element_loader.dart

Index: pkg/dev_compiler/lib/src/compiler/element_loader.dart
diff --git a/pkg/dev_compiler/lib/src/compiler/element_loader.dart b/pkg/dev_compiler/lib/src/compiler/element_loader.dart
index a2635eb26e6dcb34a7e4d6ed319e0d192a1bfb08..c99fe2a873ca97cdd8ad0cc2e4b64e3ad429a615 100644
--- a/pkg/dev_compiler/lib/src/compiler/element_loader.dart
+++ b/pkg/dev_compiler/lib/src/compiler/element_loader.dart
@@ -43,14 +43,14 @@ class ElementLoader {
   /// Subsequent [emitDeclaration] calls will cause those elements to be
   /// generated before this one, until [finishTopLevel] is called.
   void startTopLevel(Element e) {
-    assert(identical(e, currentElement));
+    assert(e == currentElement);
     _topLevelElements.add(e);
   }
 
   /// Finishes the top-level code for the element [e].
   void finishTopLevel(Element e) {
     var last = _topLevelElements.removeLast();
-    assert(identical(e, last));
+    assert(e == last);
   }
 
   /// Starts recording calls to [declareBeforeUse], until
@@ -60,7 +60,7 @@ class ElementLoader {
     // emitting top-level code.
     assert(_checkReferences == null);
     assert(_topLevelElements.isEmpty ||
-        !identical(currentElement, _topLevelElements.last));
+        currentElement != _topLevelElements.last);
     // Assume true until proven otherwise
     _checkReferences = true;
   }
@@ -85,7 +85,7 @@ class ElementLoader {
     var result = visit(node);
 
     var last = _currentElements.removeLast();
-    assert(identical(e, last));
+    assert(e == last);
 
     return result;
   }
@@ -109,7 +109,7 @@ class ElementLoader {
     }
 
     var topLevel = _topLevelElements;
-    if (topLevel.isNotEmpty && identical(currentElement, topLevel.last)) {
+    if (topLevel.isNotEmpty && currentElement == topLevel.last) {
       // If the item is from our library, try to emit it now.
       emit(e);
     }