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

lib/compiler/implementation/scanner/keyword.dart

Index: lib/compiler/implementation/scanner/keyword.dart
diff --git a/lib/compiler/implementation/scanner/keyword.dart b/lib/compiler/implementation/scanner/keyword.dart
index 1d5319ba27dd3abefb7979aaa030bd2c74e31fe0..1f4a0dfc08e5c541d514cc64e187c06fdbb1ab1a 100644
--- a/lib/compiler/implementation/scanner/keyword.dart
+++ b/lib/compiler/implementation/scanner/keyword.dart
@@ -40,6 +40,7 @@ class Keyword implements SourceString {
       const Keyword("abstract", isBuiltIn: true),
       const Keyword("as", info: AS_INFO, isBuiltIn: true),
       const Keyword("assert", isBuiltIn: true),
+      const Keyword("dynamic", isBuiltIn: true),
       const Keyword("external", isBuiltIn: true),
       const Keyword("factory", isBuiltIn: true),
       const Keyword("get", isBuiltIn: true),
@@ -59,7 +60,8 @@ class Keyword implements SourceString {
       const Keyword("show", isPseudo: true),
       const Keyword("source", isPseudo: true) ];
 
-  static const DYNAMIC = const Keyword("Dynamic", isBuiltIn: true);
+  // TODO(aprelev@gmail.com): Remove deprecated Dynamic keyword support.
+  static const DYNAMIC_DEPRECATED = const Keyword("Dynamic", isBuiltIn: true);
 
   final String syntax;
   final bool isPseudo;