Add backtrace to SLRU error reporting

Author: Konstantin Knizhnik

src/backend/access/transam/slru.c

@@ -1029,7 +1029,8 @@ SlruReportIOError(SlruCtl ctl, int pageno, TransactionId xid)
 			ereport(ERROR,
 					(errcode_for_file_access(),
 					 errmsg("could not access status of transaction %u", xid),
-					 errdetail("Could not open file \"%s\": %m.", path)));
+					 errdetail("Could not open file \"%s\": %m.", path),
+					 errbacktrace()));
 			break;
 		case SLRU_SEEK_FAILED:
 			ereport(ERROR,