Fix for reporting not analyzed parts with the new analysis driver.

pkg/analyzer_cli/lib/src/driver.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer_cli.src.driver;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io' as io;
 
@@ skipping 226 matching lines @@
         continue;
       }
       ErrorSeverity status = await _runAnalyzer(source, options);
       allResult = allResult.max(status);
       libUris.add(source.uri);
     }
 
     // Check that each part has a corresponding source in the input list.
     for (Source part in parts) {
       bool found = false;
-      for (var lib in context.getLibrariesContaining(part)) {
-        if (libUris.contains(lib.uri)) {
+      if (analysisDriver != null) {
+        var partFile = analysisDriver.fsState.getFileForPath(part.fullName);
+        if (libUris.contains(partFile.library?.uri)) {
           found = true;
         }
+      } else {
+        for (var lib in context.getLibrariesContaining(part)) {
+          if (libUris.contains(lib.uri)) {
+            found = true;
+          }
+        }
       }
       if (!found) {
         errorSink.writeln("${part.fullName} is a part and cannot be analyzed.");
         errorSink.writeln("Please pass in a library that contains this part.");
         io.exitCode = ErrorSeverity.ERROR.ordinal;
         allResult = allResult.max(ErrorSeverity.ERROR);
       }
     }
 
     if (!options.machineFormat) {
@@ skipping 677 matching lines @@
     for (var package in packages) {
       var packageName = path.basename(package.path);
       var realPath = package.resolveSymbolicLinksSync();
       result[packageName] = [
         PhysicalResourceProvider.INSTANCE.getFolder(realPath)
       ];
     }
     return result;
   }
 }