Added 'dynamic' keyword, so that 'Dynamic' can be deprecated.

lib/compiler/implementation/scanner/scanner.dart

 // Copyright (c) 2012, 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.
 
 abstract class Scanner {
   Token tokenize();
 }
 
 /**
  * Common base class for a Dart scanner.
@@ skipping 637 matching lines @@
     } else if (next < 128) {
       appendKeywordToken(state.keyword);
       return next;
     } else {
       return tokenizeIdentifier(next, start, allowDollar);
     }
   }
 
   int tokenizeIdentifier(int next, int start, bool allowDollar) {
     bool isAscii = true;
+
+    // TODO(aprelev@gmail.com): Remove deprecated Dynamic keyword support.
     bool isDynamicBuiltIn = false;
 
     if (next === $D) {
       next = advance();
       if (next === $y) {
         next = advance();
         if (next === $n) {
           next = advance();
           if (next === $a) {
             next = advance();
@@ skipping 18 matching lines @@
           ($0 <= next && next <= $9) ||
           next === $_ ||
           (next === $$ && allowDollar)) {
         isDynamicBuiltIn = false;
         next = advance();
       } else if ((next < 128) || (next === $NBSP)) {
         // Identifier ends here.
         if (start == byteOffset) {
           return error(const SourceString("expected identifier"));
         } else if (isDynamicBuiltIn) {
-          appendKeywordToken(Keyword.DYNAMIC);
+          appendKeywordToken(Keyword.DYNAMIC_DEPRECATED);
         } else if (isAscii) {
           appendByteStringToken(IDENTIFIER_INFO, asciiString(start, 0));
         } else {
           appendByteStringToken(BAD_INPUT_INFO, utf8String(start, -1));
         }
         return next;
       } else {
         isDynamicBuiltIn = false;
         int nonAsciiStart = byteOffset;
         do {
@@ skipping 156 matching lines @@
       next = advance();
     }
     return error(const SourceString("unterminated string literal"));
   }
 
   int error(SourceString message) {
     appendByteStringToken(BAD_INPUT_INFO, message);
     return advance(); // Ensure progress.
   }
 }