Make the universe parts into small libraries.

pkg/compiler/lib/src/js_backend/codegen/codegen.dart

 // Copyright (c) 2014, 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 code_generator;
 
 import 'glue.dart';
 
 import '../../closure.dart' show ClosureClassElement;
 import '../../common/codegen.dart' show CodegenRegistry;
 import '../../constants/values.dart';
 import '../../dart_types.dart';
 import '../../diagnostics/invariant.dart' show invariant;
 import '../../diagnostics/spannable.dart' show CURRENT_ELEMENT_SPANNABLE;
 import '../../elements/elements.dart';
 import '../../io/source_information.dart' show SourceInformation;
 import '../../js/js.dart' as js;
 import '../../tree_ir/tree_ir_nodes.dart' as tree_ir;
 import '../../tree_ir/tree_ir_nodes.dart' show BuiltinOperator, BuiltinMethod;
 import '../../types/types.dart' show TypeMask;
+import '../../universe/selector.dart' show
+    Selector;
 import '../../universe/universe.dart' show
-    Selector,
     UniverseSelector;
 import '../../util/maplet.dart';
 
 class CodegenBailout {
   final tree_ir.Node node;
   final String reason;
   CodegenBailout(this.node, this.reason);
   String get message {
     return 'bailout${node != null ? " on $node" : ""}: $reason';
   }
@@ skipping 89 matching lines @@
 
       // We cannot declare a variable more than once.
       if (!declaredVariables.add(use.name)) break pullFromForLoop;
 
       js.VariableInitialization jsVariable = new js.VariableInitialization(
         new js.VariableDeclaration(use.name),
         assign.value);
       jsVariables.add(jsVariable);
 
       // Remove the initializer from the for loop.
-      accumulator[accumulatorIndex] = 
+      accumulator[accumulatorIndex] =
           new js.For(null, forLoop.condition, forLoop.update, forLoop.body);
     }
 
     // Discard the statements that were pulled in the initializer.
     if (accumulatorIndex > 0) {
       accumulator = accumulator.sublist(accumulatorIndex);
     }
 
     // Declare remaining variables.
     for (tree_ir.Variable variable in variableNames.keys) {
@@ skipping 422 matching lines @@
     fallthrough.push(node);
     js.Statement body = buildBodyStatement(node.body);
     fallthrough.pop();
     shortContinue.pop();
     shortBreak.pop();
     js.Statement loopNode;
     if (node.updates.isEmpty) {
       loopNode = new js.While(condition, body);
     } else { // Compile as a for loop.
       js.Expression init;
-      if (accumulator.isNotEmpty && 
+      if (accumulator.isNotEmpty &&
           accumulator.last is js.ExpressionStatement) {
         // Take the preceding expression from the accumulator and use
         // it as the initializer expression.
         js.ExpressionStatement initStmt = accumulator.removeLast();
         init = initStmt.expression;
       }
       js.Expression update = makeSequence(node.updates);
       loopNode = new js.For(init, condition, update, body);
     }
     accumulator.add(insertLabel(node.label, loopNode));
@@ skipping 297 matching lines @@
       case BuiltinOperator.IsNotNumber:
         return js.js('typeof # !== "number"', args);
       case BuiltinOperator.IsFloor:
         return js.js('Math.floor(#) === #', args);
       case BuiltinOperator.IsNumberAndFloor:
         return js.js('typeof # === "number" && Math.floor(#) === #', args);
     }
   }
 
   /// The JS name of a built-in method.
-  static final Map<BuiltinMethod, String> builtinMethodName = 
+  static final Map<BuiltinMethod, String> builtinMethodName =
     const <BuiltinMethod, String>{
       BuiltinMethod.Push: 'push',
       BuiltinMethod.Pop: 'pop',
   };
 
   @override
   js.Expression visitApplyBuiltinMethod(tree_ir.ApplyBuiltinMethod node) {
     String name = builtinMethodName[node.method];
     js.Expression receiver = visitExpression(node.receiver);
     List<js.Expression> args = visitExpressionList(node.arguments);
     return js.js('#.#(#)', [receiver, name, args]);
   }
 
   @override
   js.Expression visitAwait(tree_ir.Await node) {
     return new js.Await(visitExpression(node.input));
   }
 
   visitFunctionExpression(tree_ir.FunctionExpression node) {
     // FunctionExpressions are currently unused.
     // We might need them if we want to emit raw JS nested functions.
     throw 'FunctionExpressions should not be used';
   }
 }