Fix the display of lock information for specktoken.

A transaction id is now displayed in the transactionid field and
speculative insertion token is displayed in the objid field.

Author: Sawada Masahiko
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CAD21AoCEKxZztULP1CDm45aSNNR1QO-Bh1q6LMTspQ78PBuJrw@mail.gmail.com

doc/src/sgml/system-views.sgml

@@ -1579,6 +1579,12 @@
    permanent transaction ID of the current holder of that row lock.
   </para>
 
+  <para>
+   A specualtive insertion lock consists of a transaction ID and a speculative
+   insertion token. The speculative insertion token is displayed in the
+   <structfield>objid</structfield> column.
+  </para>
+
   <para>
    Advisory locks can be acquired on keys consisting of either a single
    <type>bigint</type> value or two integer values.

src/backend/utils/adt/lockfuncs.c

@@ -313,6 +313,18 @@ pg_lock_status(PG_FUNCTION_ARGS)
 				nulls[8] = true;
 				nulls[9] = true;
 				break;
+			case LOCKTAG_SPECULATIVE_TOKEN:
+				values[6] =
+					TransactionIdGetDatum(instance->locktag.locktag_field1);
+				values[8] = ObjectIdGetDatum(instance->locktag.locktag_field2);
+				nulls[1] = true;
+				nulls[2] = true;
+				nulls[3] = true;
+				nulls[4] = true;
+				nulls[5] = true;
+				nulls[7] = true;
+				nulls[9] = true;
+				break;
 			case LOCKTAG_APPLY_TRANSACTION:
 				values[1] = ObjectIdGetDatum(instance->locktag.locktag_field1);
 				values[8] = ObjectIdGetDatum(instance->locktag.locktag_field2);