Update partial parser and scanner to be able to skip expressions like "new Map<S, T>()".

dart/lib/compiler/implementation/scanner/array_based_scanner.dart

 // Copyright (c) 2011, 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.
 
 class ArrayBasedScanner<S extends SourceString> extends AbstractScanner<S> {
   int get charOffset() => byteOffset + extraCharOffset;
   final Token tokens;
   Token tail;
   int tokenStart;
   int byteOffset;
@@ skipping 31 matching lines @@
     tail.next = new Token(info, tokenStart);
     tail = tail.next;
   }
 
   void appendStringToken(PrecedenceInfo info, String value) {
     tail.next = new StringToken(info, value, tokenStart);
     tail = tail.next;
   }
 
   void appendKeywordToken(Keyword keyword) {
+    String syntax = keyword.syntax;
+
+    // Type parameters and arguments cannot contain 'this' or 'super'.
+    if (syntax === 'this' || syntax === 'super') discardOpenLt();
     tail.next = new KeywordToken(keyword, tokenStart);
     tail = tail.next;
   }
 
   void appendEofToken() {
     tail.next = new Token(EOF_INFO, charOffset);
     tail = tail.next;
     // EOF points to itself so there's always infinite look-ahead.
     tail.next = tail;
     discardOpenLt();
@@ skipping 21 matching lines @@
   }
 
   void appendWhiteSpace(int next) {
     // Do nothing, we don't collect white space.
   }
 
   void appendBeginGroup(PrecedenceInfo info, String value) {
     Token token = new BeginGroupToken(info, value, tokenStart);
     tail.next = token;
     tail = tail.next;
-    while (info.kind !== LT_TOKEN &&
-           !groupingStack.isEmpty() &&
-           groupingStack.head.kind === LT_TOKEN) {
-      groupingStack = groupingStack.tail;
-    }
+    if (info.kind !== LT_TOKEN) discardOpenLt();
     groupingStack = groupingStack.prepend(token);
   }
 
   int appendEndGroup(PrecedenceInfo info, String value, int openKind) {
     assert(openKind !== LT_TOKEN);
     appendStringToken(info, value);
     discardOpenLt();
     if (groupingStack.isEmpty()) {
       return advance();
     }
@@ skipping 58 matching lines @@
 
   void discardOpenLt() {
     while (!groupingStack.isEmpty() && groupingStack.head.kind === LT_TOKEN) {
       groupingStack = groupingStack.tail;
     }
   }
 
   // TODO(ahe): make class abstract instead of adding an abstract method.
   abstract peek();
 }