Fix for indexing synthetic getter/setter references.

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

Index: pkg/analyzer/lib/src/summary/index_unit.dart
diff --git a/pkg/analyzer/lib/src/summary/index_unit.dart b/pkg/analyzer/lib/src/summary/index_unit.dart
index a6289a85bab3547a4cab48fc1d5dc2a14cfe28d3..569dddd8a29bedbea33ea373124511da34d136cc 100644
--- a/pkg/analyzer/lib/src/summary/index_unit.dart
+++ b/pkg/analyzer/lib/src/summary/index_unit.dart
@@ -212,7 +212,7 @@ class PackageIndexAssembler {
         kind = accessor.isGetter
             ? IndexSyntheticElementKind.getter
             : IndexSyntheticElementKind.setter;
-        element = element.enclosingElement;
+        element = accessor.variable;
       } else if (element is TopLevelVariableElement) {
         TopLevelVariableElement property = element;
         kind = IndexSyntheticElementKind.topLevelVariable;