Prohibit creating ICU collation with different ctype

ICU does not support "collate" and "ctype" being different, so the
collctype catalog column is ignored.  But for catalog neatness, ensure
that they are the same.

src/backend/utils/adt/pg_locale.c

@@ -1354,6 +1354,11 @@ pg_newlocale_from_collation(Oid collid)
 			UCollator  *collator;
 			UErrorCode	status;
 
+			if (strcmp(collcollate, collctype) != 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("collations with different collate and ctype values are not supported by ICU")));
+
 			status = U_ZERO_ERROR;
 			collator = ucol_open(collcollate, &status);
 			if (U_FAILURE(status))