Fix ALTER TABLE so that the array type gets the same OID in all segments.

The out/readfuncs.c support for AlterTableStmt.comptypeArrayOid was
missing. Because of that, the segments didn't get the OID of the composite
type's array type from master, and allocated it on their own.

src/backend/nodes/outfuncs.c

@@ -2525,6 +2525,7 @@ _outAlterTableStmt(StringInfo str, AlterTableStmt *node)
 	{
 		WRITE_OID_FIELD(oidInfo[m].relOid);
 		WRITE_OID_FIELD(oidInfo[m].comptypeOid);
+		WRITE_OID_FIELD(oidInfo[m].comptypeArrayOid);
 		WRITE_OID_FIELD(oidInfo[m].toastOid);
 		WRITE_OID_FIELD(oidInfo[m].toastIndexOid);
 		WRITE_OID_FIELD(oidInfo[m].toastComptypeOid);

src/backend/nodes/readfast.c

@@ -568,6 +568,7 @@ _readAlterTableStmt(void)
 		{
 			READ_OID_FIELD(oidInfo[m].relOid);
 			READ_OID_FIELD(oidInfo[m].comptypeOid);
+			READ_OID_FIELD(oidInfo[m].comptypeArrayOid);
 			READ_OID_FIELD(oidInfo[m].toastOid);
 			READ_OID_FIELD(oidInfo[m].toastIndexOid);
 			READ_OID_FIELD(oidInfo[m].toastComptypeOid);

src/backend/nodes/readfuncs.c

@@ -1077,6 +1077,7 @@ _readAlterTableStmt(void)
 		{
 			READ_OID_FIELD(oidInfo[m].relOid);
 			READ_OID_FIELD(oidInfo[m].comptypeOid);
+			READ_OID_FIELD(oidInfo[m].comptypeArrayOid);
 			READ_OID_FIELD(oidInfo[m].toastOid);
 			READ_OID_FIELD(oidInfo[m].toastIndexOid);
 			READ_OID_FIELD(oidInfo[m].toastComptypeOid);