Dynamically load packages for dartdevc tests in test.dart.

pkg/dev_compiler/lib/src/compiler/compiler.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:collection' show HashSet, Queue;
 import 'dart:convert' show JSON;
 import 'dart:io' show File;
 
 import 'package:analyzer/analyzer.dart'
     show AnalysisError, CompilationUnit, ErrorSeverity;
@@ skipping 236 matching lines @@
   final bool inlineSourceMap;
 
   /// Whether to emit a summary file containing API signatures.
   ///
   /// This is required for a modular build process.
   final bool summarizeApi;
 
   /// The file extension for summaries.
   final String summaryExtension;
 
-  /// Whether to preserve metdata only accessible via mirrors
+  /// Whether to preserve metdata only accessible via mirrors.
   final bool emitMetadata;
 
   /// Whether to force compilation of code with static errors.
   final bool unsafeForceCompile;
 
   /// Whether to compile code in a more permissive REPL mode allowing access
   /// to private members across library boundaries.
   final bool replCompile;
 
   /// Whether to emit Closure Compiler-friendly code.
   final bool closure;
 
-  /// Hoist the types at instance creation sites
+  /// Hoist the types at instance creation sites.
   final bool hoistInstanceCreation;
 
-  /// Hoist types from class signatures
+  /// Hoist types from class signatures.
   final bool hoistSignatureTypes;
 
-  /// Name types in type tests
+  /// Name types in type tests.
   final bool nameTypeTests;
 
-  /// Hoist types in type tests
+  /// Hoist types in type tests.
   final bool hoistTypeTests;
 
   /// Enable ES6 destructuring of named parameters. Off by default.
   ///
   /// Older V8 versions do not accept default values with destructuring in
   /// arrow functions yet (e.g. `({a} = {}) => 1`) but happily accepts them
   /// with regular functions (e.g. `function({a} = {}) { return 1 }`).
   ///
   /// Supporting the syntax:
   /// * Chrome Canary (51)
@@ skipping 337 matching lines @@
     case "dart":
     case "package":
     case "file":
       // A valid URI.
       return uri;
     default:
       // Assume a file path.
       return new Uri.file(path.absolute(source));
   }
 }