Allow closures inside lazy initializers.

lib/compiler/implementation/elements/elements.dart

Index: lib/compiler/implementation/elements/elements.dart
diff --git a/lib/compiler/implementation/elements/elements.dart b/lib/compiler/implementation/elements/elements.dart
index 9877fe7daba1d0560bf357351123c8c6eca62e66..2594b087145e86e0f1cc27273207cf5d4f71eb44 100644
--- a/lib/compiler/implementation/elements/elements.dart
+++ b/lib/compiler/implementation/elements/elements.dart
@@ -247,11 +247,7 @@ class Element implements Spannable {
 
   CompilationUnitElement getCompilationUnit() {
     Element element = this;
-    while (element !== null && !element.isCompilationUnit()) {
-      if (element.isLibrary()) {
-        LibraryElement library = element;
-        return library.entryCompilationUnit;
-      }
+    while (!element.isCompilationUnit()) {
       element = element.enclosingElement;
     }
     return element;
@@ -614,6 +610,8 @@ class LibraryElement extends ScopeContainerElement {
   LibraryElement get declaration => super.declaration;
   LibraryElement get implementation => super.implementation;
 
+  CompilationUnitElement getCompilationUnit() => entryCompilationUnit;
+
   void addCompilationUnit(CompilationUnitElement element) {
     compilationUnits = compilationUnits.prepend(element);
   }