Refactoring

Src/AST/Myc.Ast.Visitor.pas

@@ -579,7 +579,7 @@ begin
         exit(Node);
 
     // The body changed. Create a NEW wrapper node.
-    Result := TMacroExpansionNode.Create(Node.CallNode, newBody);
+    Result := TAst.MacroExpansionNode(Node.CallNode, newBody);
 end;
 
 function TAstTransformer.VisitBlockExpression(const Node: IBlockExpressionNode): IAstNode;