should be it

external/duckdb/third_party/libpg_query/include/mb/pg_wchar.hpp

@@ -0,0 +1,28 @@
+/*-------------------------------------------------------------------------
+ *
+ * pg_wchar.h
+ *	  multibyte-character support
+ *
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development PGGroup
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/mb/pg_wchar.h
+ *
+ *	NOTES
+ *		This is used both by the backend and by libpq, but should not be
+ *		included by libpq client programs.  In particular, a libpq client
+ *		should not assume that the encoding IDs used by the version of libpq
+ *		it's linked to match up with the IDs declared here.
+ *
+ *-------------------------------------------------------------------------
+ */
+#pragma once
+
+#include <cstdint>
+
+/*
+ * The pg_wchar type
+ */
+namespace duckdb_libpgquery {
+typedef unsigned int pg_wchar;
+}