Enable strong mode in DDC, fix all warnings/errors

lib/src/js_ast/builder.dart

 // Copyright (c) 2013, 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.
 
 // Utilities for building JS ASTs at runtime.  Contains a builder class
 // and a parser that parses part of the language.
 
 part of js_ast;
 
 
@@ skipping 1136 matching lines @@
     while (acceptCategory(COMMA)) {
       Expression right = parseAssignment();
       expression = new Binary(',', expression, right);
     }
     return expression;
   }
 
   /** Parse a variable declaration list, with `var` or `let` [keyword] */
   VariableDeclarationList parseVariableDeclarationList(
       String keyword, [String firstIdentifier])  {
-    var initialization = [];
+    var initialization = <VariableInitialization>[];
 
     do {
       var declarator;
       if (firstIdentifier != null) {
         declarator = new Identifier(firstIdentifier);
         firstIdentifier = null;
       } else {
         declarator = parseVariableBinding();
       }
 
@@ skipping 339 matching lines @@
     Expression expression = null;
     if (acceptString('case')) {
       expression = parseExpression();
       expectCategory(COLON);
     } else {
       if (!acceptString('default')) {
         error('expected case or default');
       }
       expectCategory(COLON);
     }
-    List statements = new List<Statement>();
+    var statements = <Statement>[];
     while (lastCategory != RBRACE &&
            lastToken != 'case' &&
            lastToken != 'default') {
       statements.add(parseStatement());
     }
     return expression == null
         ? new Default(new Block(statements))
         : new Case(expression, new Block(statements));
   }
 
@@ skipping 114 matching lines @@
       expectCategory(RSQUARE);
       return expr;
     } else if (acceptCategory(HASH)) {
       return parseInterpolatedExpression();
     } else {
       error('Expected property name');
       return null;
     }
   }
 }