Add summary support for ConstructorElement.nameEnd and .periodOffset.

pkg/analyzer/lib/src/summary/resynthesize.dart

Index: pkg/analyzer/lib/src/summary/resynthesize.dart
diff --git a/pkg/analyzer/lib/src/summary/resynthesize.dart b/pkg/analyzer/lib/src/summary/resynthesize.dart
index 1d27fc29747cbf2390352e8ebc4c7699b7f3c63d..40c9a9b2e9619fa3c8b1f5cc195c959ebd0152a1 100644
--- a/pkg/analyzer/lib/src/summary/resynthesize.dart
+++ b/pkg/analyzer/lib/src/summary/resynthesize.dart
@@ -1062,6 +1062,13 @@ class _LibraryResynthesizer {
     assert(serializedExecutable.kind == UnlinkedExecutableKind.constructor);
     currentConstructor = new ConstructorElementImpl(
         serializedExecutable.name, serializedExecutable.nameOffset);
+    if (serializedExecutable.name.isEmpty) {
+      currentConstructor.nameEnd =
+          serializedExecutable.nameOffset + classType.name.length;
+    } else {
+      currentConstructor.nameEnd = serializedExecutable.nameEnd;
+      currentConstructor.periodOffset = serializedExecutable.periodOffset;
+    }
     constructors[serializedExecutable.name] = currentConstructor;
     currentConstructor.returnType = classType;
     buildExecutableCommonParts(currentConstructor, serializedExecutable);