Refactor other replication commands to use DestRemoteSimple.

Commit a84069d935 added a new type of
DestReceiver to avoid duplicating the existing code for the SHOW
command, but it turns out we can leverage that new DestReceiver
type in a few more places, saving some code.

Michael Paquier, reviewed by Andres Freund and by me.

Discussion: http://postgr.es/m/CAB7nPqSdFOQC0evc0r1nJeQyGBqjBrR41MC4rcMqUUpoJaZbtQ%40mail.gmail.com
Discussion: http://postgr.es/m/CAB7nPqT2K4XFT1JgqufFBjsOc-NUKXg5qBDucHPMbk6Xi1kYaA@mail.gmail.com

src/backend/access/common/printsimple.c

@@ -22,6 +22,7 @@
 #include "catalog/pg_type.h"
 #include "fmgr.h"
 #include "libpq/pqformat.h"
+#include "utils/builtins.h"
 
 /*
  * At startup time, send a RowDescription message.
@@ -99,6 +100,26 @@ printsimple(TupleTableSlot *slot, DestReceiver *self)
 				}
 				break;
 
+			case INT4OID:
+				{
+					int32	num = DatumGetInt32(value);
+					char	str[12];	/* sign, 10 digits and '\0' */
+
+					pg_ltoa(num, str);
+					pq_sendcountedtext(&buf, str, strlen(str), false);
+				}
+				break;
+
+			case INT8OID:
+				{
+					int64	num = DatumGetInt64(value);
+					char	str[23];	/* sign, 21 digits and '\0' */
+
+					pg_lltoa(num, str);
+					pq_sendcountedtext(&buf, str, strlen(str), false);
+				}
+				break;
+
 			default:
 				elog(ERROR, "unsupported type OID: %u", attr->atttypid);
 		}