Add guc lc_ctype back

Author: baobao0206

src/backend/utils/adt/pg_locale.c

@@ -97,6 +97,7 @@
 
 
 /* GUC settings */
+char	   *locale_ctype;
 char	   *locale_messages;
 char	   *locale_monetary;
 char	   *locale_numeric;

src/backend/utils/misc/guc_tables.c

@@ -4147,6 +4147,17 @@ struct config_string ConfigureNamesString[] =
 		NULL, NULL, NULL
 	},
 
+	{
+			{"lc_ctype", PGC_INTERNAL, PRESET_OPTIONS,
+					gettext_noop("Shows the character classification and case conversion locale."),
+					NULL,
+					GUC_NOT_IN_SAMPLE | GUC_DISALLOW_IN_FILE
+			},
+			&locale_ctype,
+			"C",
+			NULL, NULL, NULL
+	},
+	
 	/* See main.c about why defaults for LC_foo are not all alike */
 
 	{

src/include/utils/pg_locale.h

@@ -36,6 +36,7 @@
 #define LOCALE_NAME_BUFLEN 128
 
 /* GUC settings */
+extern PGDLLIMPORT char *locale_ctype;
 extern PGDLLIMPORT char *locale_messages;
 extern PGDLLIMPORT char *locale_monetary;
 extern PGDLLIMPORT char *locale_numeric;