PR c/79022 fix mismatch parameter order in declaratio

The declaration of create_nested_ptr_option in the header has the 'from'
and 'to' parameters in the opposite order from the definition in
gengtype.c:

  /* Return an options structure for a "nested_ptr" option.  */
  options_p
  create_nested_ptr_option (options_p next, type_p t,
                            const char *to, const char *from)

and the only caller in gengtype-parse.c:

  return create_nested_ptr_option (prev, ty, to, from);

This patch swaps the parameter names in the declaration.

	PR c/79022
	* gengtype.h (create_nested_ptr_option): Fix parameter names to match
	definition.

From-SVN: r269990

gcc/ChangeLog

+2019-03-28  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR c/79022
+	* gengtype.h (create_nested_ptr_option): Fix parameter names to match
+	definition.
+
 2019-03-27  Mateusz B  <mateuszb@poczta.onet.pl>
 
 	PR target/85667

gcc/gengtype.h

@@ -203,8 +203,8 @@ options_p create_nested_option (options_p next, const char* name,
 				struct nested_ptr_data* info);
 
 /* Create a nested pointer option.  */
-options_p create_nested_ptr_option (options_p, type_p t,
-			 	     const char *from, const char *to);
+options_p create_nested_ptr_option (options_p next, type_p t,
+				    const char *to, const char *from);
 
 /* A name and a type.  */
 struct pair {