Support symbol literals.

sdk/lib/_internal/compiler/implementation/ssa/builder.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.
 
 part of ssa;
 
 /**
  * A special element for the extra parameter taken by intercepted
  * methods. We need to override [Element.computeType] because our
  * optimizers may look at its declared type.
@@ skipping 4037 matching lines @@
     stack.add(graph.addConstantDouble(node.value, compiler));
   }
 
   void visitLiteralBool(LiteralBool node) {
     stack.add(graph.addConstantBool(node.value, compiler));
   }
 
   void visitLiteralString(LiteralString node) {
     stack.add(graph.addConstantString(node.dartString, node, compiler));
   }
+  
+  void visitSymbolLiteral(SymbolLiteral node) {
+    ConstantHandler handler = compiler.constantHandler;
+    ConstructedConstant constant = 
+        handler.compileNodeWithDefinitions(node, elements);
+    stack.add(graph.addConstant(constant, compiler));
+    compiler.enqueuer.codegen.registerConstSymbol(node.nameString, elements);
+  }
 
   void visitStringJuxtaposition(StringJuxtaposition node) {
     if (!node.isInterpolation) {
       // This is a simple string with no interpolations.
       stack.add(graph.addConstantString(node.dartString, node, compiler));
       return;
     }
     StringBuilderVisitor stringBuilder = new StringBuilderVisitor(this, node);
     stringBuilder.visit(node);
     stack.add(stringBuilder.result);
@@ skipping 1384 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }