More logically order libpq func. includes, e.g., group GUC vals

Reported-by: David Zhang

Discussion: https://postgr.es/m/65909efe-97c6-4863-af4e-21eb5a26dd1e@highgo.ca

Co-authored-by: David Zhang

Backpatch-through: master

Author: bmomjian

src/include/libpq/libpq.h

@@ -86,19 +86,6 @@ extern bool pq_check_connection(void);
 /*
  * prototypes for functions in be-secure.c
  */
-extern PGDLLIMPORT char *ssl_library;
-extern PGDLLIMPORT char *ssl_cert_file;
-extern PGDLLIMPORT char *ssl_key_file;
-extern PGDLLIMPORT char *ssl_ca_file;
-extern PGDLLIMPORT char *ssl_crl_file;
-extern PGDLLIMPORT char *ssl_crl_dir;
-extern PGDLLIMPORT char *ssl_dh_params_file;
-extern PGDLLIMPORT char *ssl_passphrase_command;
-extern PGDLLIMPORT bool ssl_passphrase_command_supports_reload;
-#ifdef USE_SSL
-extern PGDLLIMPORT bool ssl_loaded_verify_locations;
-#endif
-
 extern int	secure_initialize(bool isServerStart);
 extern bool secure_loaded_verify_locations(void);
 extern void secure_destroy(void);
@@ -110,19 +97,33 @@ extern ssize_t secure_raw_read(Port *port, void *ptr, size_t len);
 extern ssize_t secure_raw_write(Port *port, const void *ptr, size_t len);
 
 /*
- * prototypes for functions in be-secure-gssapi.c
+ * declarations for variables defined in be-secure.c
  */
-#ifdef ENABLE_GSS
-extern ssize_t secure_open_gssapi(Port *port);
-#endif
-
-/* GUCs */
+extern PGDLLIMPORT char *ssl_library;
+extern PGDLLIMPORT char *ssl_ca_file;
+extern PGDLLIMPORT char *ssl_cert_file;
+extern PGDLLIMPORT char *ssl_crl_file;
+extern PGDLLIMPORT char *ssl_crl_dir;
+extern PGDLLIMPORT char *ssl_key_file;
+extern PGDLLIMPORT int ssl_min_protocol_version;
+extern PGDLLIMPORT int ssl_max_protocol_version;
+extern PGDLLIMPORT char *ssl_passphrase_command;
+extern PGDLLIMPORT bool ssl_passphrase_command_supports_reload;
+extern PGDLLIMPORT char *ssl_dh_params_file;
 extern PGDLLIMPORT char *SSLCipherSuites;
 extern PGDLLIMPORT char *SSLCipherList;
 extern PGDLLIMPORT char *SSLECDHCurve;
 extern PGDLLIMPORT bool SSLPreferServerCiphers;
-extern PGDLLIMPORT int ssl_min_protocol_version;
-extern PGDLLIMPORT int ssl_max_protocol_version;
+#ifdef USE_SSL
+extern PGDLLIMPORT bool ssl_loaded_verify_locations;
+#endif
+
+/*
+ * prototypes for functions in be-secure-gssapi.c
+ */
+#ifdef ENABLE_GSS
+extern ssize_t secure_open_gssapi(Port *port);
+#endif
 
 enum ssl_protocol_versions
 {