Resynthesize ConstructorElement.redirectedConstructor lazily.

pkg/analyzer/lib/src/dart/element/element.dart

Index: pkg/analyzer/lib/src/dart/element/element.dart
diff --git a/pkg/analyzer/lib/src/dart/element/element.dart b/pkg/analyzer/lib/src/dart/element/element.dart
index 636e0e995200fafd654dbb68c66c49e299c7aa45..7c1e056917cbf7af237cbf95e6229ffb651e92c1 100644
--- a/pkg/analyzer/lib/src/dart/element/element.dart
+++ b/pkg/analyzer/lib/src/dart/element/element.dart
@@ -1685,7 +1685,7 @@ class ConstructorElementImpl extends ExecutableElementImpl
   /**
    * The constructor to which this constructor is redirecting.
    */
-  ConstructorElement redirectedConstructor;
+  ConstructorElement _redirectedConstructor;
 
   /**
    * The initializers for this constructor (used for evaluating constant
@@ -1756,7 +1756,8 @@ class ConstructorElementImpl extends ExecutableElementImpl
   }
 
   @override
-  ClassElement get enclosingElement => super.enclosingElement as ClassElement;
+  ClassElementImpl get enclosingElement =>
+      super.enclosingElement as ClassElementImpl;
 
   @override
   TypeParameterizedElementMixin get enclosingTypeParameterContext =>
@@ -1855,6 +1856,30 @@ class ConstructorElementImpl extends ExecutableElementImpl
   }
 
   @override
+  ConstructorElement get redirectedConstructor {
+    if (serializedExecutable != null && _redirectedConstructor == null) {
+      if (serializedExecutable.isRedirectedConstructor) {
+        if (serializedExecutable.isFactory) {
+          _redirectedConstructor = enclosingUnit.resynthesizerContext
+              .resolveConstructorRef(
+                  enclosingElement, serializedExecutable.redirectedConstructor);
+        } else {
+          _redirectedConstructor = enclosingElement.getNamedConstructor(
+              serializedExecutable.redirectedConstructorName);
+        }
+      } else {
+        return null;
+      }
+    }
+    return _redirectedConstructor;
+  }
+
+  void set redirectedConstructor(ConstructorElement redirectedConstructor) {
+    assert(serializedExecutable == null);
+    _redirectedConstructor = redirectedConstructor;
+  }
+
+  @override
   DartType get returnType => enclosingElement.type;
 
   @override
@@ -7369,6 +7394,13 @@ abstract class ResynthesizerContext {
   UnitExplicitTopLevelVariables buildTopLevelVariables();
 
   /**
+   * Resolve an [EntityRef] into a constructor.  If the reference is
+   * unresolved, return `null`.
+   */
+  ConstructorElement resolveConstructorRef(
+      TypeParameterizedElementMixin typeParameterContext, EntityRef entry);
+
+  /**
    * Build the appropriate [DartType] object corresponding to a slot id in the
    * [LinkedUnit.types] table.
    */