Move parser and token related libraries into their own subfolder.

pkg/compiler/lib/src/parser/diet_parser_task.dart

Index: pkg/compiler/lib/src/parser/diet_parser_task.dart
diff --git a/pkg/compiler/lib/src/scanner/diet_parser_task.dart b/pkg/compiler/lib/src/parser/diet_parser_task.dart
similarity index 97%
rename from pkg/compiler/lib/src/scanner/diet_parser_task.dart
rename to pkg/compiler/lib/src/parser/diet_parser_task.dart
index ec60a2df0c87cc2dad200a01085cd0c3f855bba3..971d92cab0a6c67ee9695dab05abc7af5bc88700 100644
--- a/pkg/compiler/lib/src/scanner/diet_parser_task.dart
+++ b/pkg/compiler/lib/src/parser/diet_parser_task.dart
@@ -12,14 +12,14 @@ import '../elements/elements.dart' show
     CompilationUnitElement;
 import '../diagnostics/invariant.dart' show
     invariant;
+import '../tokens/token.dart' show
+    Token;
 
 import 'listener.dart' show
     ElementListener,
     ParserError;
 import 'partial_parser.dart' show
     PartialParser;
-import 'token.dart' show
-    Token;
 
 class DietParserTask extends CompilerTask {
   DietParserTask(Compiler compiler) : super(compiler);