Remove incorrect assertion

The MemTupleNoOidSpace() wasn't implemented and did just do an
assertion rather than what it said on the tin. Remove since the
intention of the macro isn't really possible - there is nothing
like HEAP_HASOID for memtuples.

src/backend/access/appendonly/appendonlyam.c

@@ -2889,11 +2889,6 @@ appendonly_insert_init(Relation rel, int segno, bool update_mode)
 		if (!OidIsValid(MemTupleGetOid(instup, aoInsertDesc->mt_bind)))
 			MemTupleSetOid(instup, aoInsertDesc->mt_bind, GetNewOid(relation));
 	}
-	else
-	{
-		/* check there is not space for an OID */
-		MemTupleNoOidSpace(instup);
-	}
 
 	if (aoInsertDesc->useNoToast)
 		need_toast = false;

src/include/access/memtup.h

@@ -9,15 +9,6 @@
 
 #include "access/tupdesc.h"
 
-/* 
- * TODO: implement this macro - equivalent
- * in functionality to the the following check
- * Assert(!(tup->t_data->t_infomask & HEAP_HASOID));
- * it's a sanity check.
- */
-#define MemTupleNoOidSpace(tuple) Assert(tuple) \
-
-
 typedef enum MemTupleBindFlag
 {
 	MTB_ByVal_Native = 1,	/* Fixed len, native (returned as datum ) */