Record information about parts of dependent libraries in summaries.

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

Index: pkg/analyzer/lib/src/summary/prelink.dart
diff --git a/pkg/analyzer/lib/src/summary/prelink.dart b/pkg/analyzer/lib/src/summary/prelink.dart
index bfa20ca561ca292e9fad6bbda2d5a1172ba68219..ad4834f1f738e8bb0270d00393349ea484afc398 100644
--- a/pkg/analyzer/lib/src/summary/prelink.dart
+++ b/pkg/analyzer/lib/src/summary/prelink.dart
@@ -156,11 +156,13 @@ class _Prelinker {
     assert(dependencies.length == dependencyToPublicNamespace.length);
     int dependency = dependencies.length;
     uriToDependency[relativeUri] = dependency;
-    dependencies.add(encodePrelinkedDependency(uri: relativeUri));
+    List<String> unitUris = getUnitUris(relativeUri);
+    PrelinkedDependencyBuilder prelinkedDependency =
+        encodePrelinkedDependency(uri: relativeUri, parts: unitUris.sublist(1));
+    dependencies.add(prelinkedDependency);
 
     Map<String, _Meaning> aggregated = <String, _Meaning>{};
 
-    List<String> unitUris = getUnitUris(relativeUri);
     for (int unitNum = 0; unitNum < unitUris.length; unitNum++) {
       String unitUri = unitUris[unitNum];
       UnlinkedPublicNamespace importedNamespace = getImportCached(unitUri);