[cleanup] remove PropertyName from js_ast

lib/src/js/template.dart

Index: lib/src/js/template.dart
diff --git a/lib/src/js/template.dart b/lib/src/js/template.dart
index 8c5c473db2bdb7d5a40fc11f86a6ff0168a3f983..32ad536f6b8c5f45a0935457857f3946702ad978 100644
--- a/lib/src/js/template.dart
+++ b/lib/src/js/template.dart
@@ -274,17 +274,6 @@ class InstantiatorGeneratorVisitor implements NodeVisitor<Instantiator> {
     };
   }
 
-  Instantiator visitInterpolatedPropertyName(InterpolatedPropertyName node) {
-    var nameOrPosition = node.nameOrPosition;
-    return (arguments) {
-      var item = arguments[nameOrPosition];
-      if (item is PropertyName) return item;
-      if (item is String) return new PropertyName(item);
-      return error('Interpolated value #$nameOrPosition is not a '
-          'PropertyName or String: $item');
-    };
-  }
-
   Instantiator visitInterpolatedVariableDeclaration(
         InterpolatedVariableDeclaration node) {
     var nameOrPosition = node.nameOrPosition;
@@ -752,9 +741,6 @@ class InstantiatorGeneratorVisitor implements NodeVisitor<Instantiator> {
     };
   }
 
-  Instantiator visitPropertyName(PropertyName node) =>
-      (arguments) => new PropertyName(node.name);
-
   Instantiator visitRegExpLiteral(RegExpLiteral node) =>
       (arguments) => new RegExpLiteral(node.pattern);