Add UnlinkedUnit.isPartOf flag.

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

Index: pkg/analyzer/lib/src/summary/idl.dart
diff --git a/pkg/analyzer/lib/src/summary/idl.dart b/pkg/analyzer/lib/src/summary/idl.dart
index c67dee6e45a71674b3a784236b01babb3da9daf7..ddb353c0be18d893759472c99d21cc2d13131338 100644
--- a/pkg/analyzer/lib/src/summary/idl.dart
+++ b/pkg/analyzer/lib/src/summary/idl.dart
@@ -2695,6 +2695,12 @@ abstract class UnlinkedUnit extends base.SummaryClass {
   List<UnlinkedImport> get imports;
 
   /**
+   * Indicates whether the unit is a part-of a library.

[Paul Berry, 2016/10/31 20:20:50]

Nit: let's change this doc comment to something like:

"Indicates whether the unit contains a "part of" declaration.

(Since it's possible, in invalid code, to have a mismatch between "part" and
"part of" declarations, I want to make sure it's absolutely clear that this
boolean is based solely on the contents of the file being analyzed; it does not
depend on whether some other file actually has a "part" declaration that points
to this file).

[scheglov, 2016/10/31 21:01:57]

Done.

+   */
+  @Id(18)
+  bool get isPartOf;
+
+  /**
    * Annotations for the library declaration, or the empty list if there is no
    * library declaration.
    */