Fix default AstVisitor.visitRow implementation

Row is an Expression, so it should delegate to visitExpression
instead of jumping directly to visitNode

presto-parser/src/main/java/io/prestosql/sql/tree/AstVisitor.java

@@ -449,7 +449,7 @@ protected R visitValues(Values node, C context)
 
     protected R visitRow(Row node, C context)
     {
-        return visitNode(node, context);
+        return visitExpression(node, context);
     }
 
     protected R visitTableSubquery(TableSubquery node, C context)