Include the common library name used in 'part of' directives.

pkg/analyzer/lib/src/generated/error.dart

Index: pkg/analyzer/lib/src/generated/error.dart
diff --git a/pkg/analyzer/lib/src/generated/error.dart b/pkg/analyzer/lib/src/generated/error.dart
index 8c27bc0cb281d5534071638008da06a73bfcef16..7e5219708cdb619fa998aa7bb21d7cfe3d597289 100644
--- a/pkg/analyzer/lib/src/generated/error.dart
+++ b/pkg/analyzer/lib/src/generated/error.dart
@@ -237,7 +237,7 @@ class AnalysisErrorWithProperties extends AnalysisError {
    * used to complete the message. The error has no location information.
    */
   AnalysisErrorWithProperties.con1(
-      Source source, ErrorCode errorCode, List<Object> arguments)
+      Source source, ErrorCode errorCode, [List<Object> arguments])
       : super.con1(source, errorCode, arguments);
 
   /**
@@ -2377,13 +2377,24 @@ abstract class ErrorCode {
  */
 class ErrorProperty extends Enum<ErrorProperty> {
   /**
-   * A property whose value is an array of [ExecutableElement] that should
+   * A property whose value is the name of the library that is used by all
+   * of the "part of" directives, so should be used in the "library" directive.
+   * Is `null` if there is no a single name used by all of the parts.
+   */
+  static const ErrorProperty PARTS_LIBRARY_NAME =
+      const ErrorProperty('PARTS_LIBRARY_NAME', 0);
+
+  /**
+   * A property whose value is a list of [ExecutableElement] that should
    * be but are not implemented by a concrete class.
    */
   static const ErrorProperty UNIMPLEMENTED_METHODS =
-      const ErrorProperty('UNIMPLEMENTED_METHODS', 0);
+      const ErrorProperty('UNIMPLEMENTED_METHODS', 1);
 
-  static const List<ErrorProperty> values = const [UNIMPLEMENTED_METHODS];
+  static const List<ErrorProperty> values = const [
+    PARTS_LIBRARY_NAME,
+    UNIMPLEMENTED_METHODS
+  ];
 
   const ErrorProperty(String name, int ordinal) : super(name, ordinal);
 }