Fixes #519

lib/src/compiler/code_generator.dart

Index: lib/src/compiler/code_generator.dart
diff --git a/lib/src/compiler/code_generator.dart b/lib/src/compiler/code_generator.dart
index 78636a1fee364daef6630174b4d6576d594ba010..2c19b39ef6f2c7ac0a9af6e10978145d953ec503 100644
--- a/lib/src/compiler/code_generator.dart
+++ b/lib/src/compiler/code_generator.dart
@@ -3430,11 +3430,11 @@ class CodeGenerator extends GeneralizingAstVisitor
 
   @override
   visitSymbolLiteral(SymbolLiteral node) {
-    JS.New emitSymbol() {
+    JS.Expression emitSymbol() {
       // TODO(vsm): When we canonicalize, we need to treat private symbols
       // correctly.
       var name = js.string(node.components.join('.'), "'");
-      return new JS.New(_emitTypeName(types.symbolType), [name]);

[vsm, 2016/04/22 18:23:49]

Note: we need #.new to invoke the factory constructor on core.Symbol (which is
an abstract class).  We were instantiating the abstract class instead.

[Jennifer Messerly, 2016/04/25 16:31:08]

Nice. I wonder if instead of hard coding we should try and go through the normal
emitConstructor code path? That would prevent this kind of bug from recurring in
the future :)

+      return js.call('#.new(#)', [_emitTypeName(types.symbolType), name]);
     }
     return _emitConst(emitSymbol);
   }