doc: mention the pg_locks lock names in parentheses

Reported-by: Troy Frericks

Discussion: https://postgr.es/m/165653551130.665.8240515669521441325@wrigleys.postgresql.org

Backpatch-through: 10

doc/src/sgml/mvcc.sgml

@@ -875,7 +875,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
       <title>Table-Level Lock Modes</title>
       <varlistentry>
        <term>
-        <literal>ACCESS SHARE</literal>
+        <literal>ACCESS SHARE</literal> (<literal>AccessShareLock</literal>)
        </term>
        <listitem>
         <para>
@@ -893,7 +893,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
 
       <varlistentry>
        <term>
-        <literal>ROW SHARE</literal>
+        <literal>ROW SHARE</literal> (<literal>RowShareLock</literal>)
        </term>
        <listitem>
         <para>
@@ -914,7 +914,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
 
       <varlistentry>
        <term>
-        <literal>ROW EXCLUSIVE</literal>
+        <literal>ROW EXCLUSIVE</literal> (<literal>RowExclusiveLock</literal>)
        </term>
        <listitem>
         <para>
@@ -936,7 +936,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
 
       <varlistentry>
        <term>
-        <literal>SHARE UPDATE EXCLUSIVE</literal>
+        <literal>SHARE UPDATE EXCLUSIVE</literal> (<literal>ShareUpdateExclusiveLock</literal>)
        </term>
        <listitem>
         <para>
@@ -962,7 +962,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
 
       <varlistentry>
        <term>
-        <literal>SHARE</literal>
+        <literal>SHARE</literal> (<literal>ShareLock</literal>)
        </term>
        <listitem>
         <para>
@@ -982,7 +982,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
 
       <varlistentry>
        <term>
-        <literal>SHARE ROW EXCLUSIVE</literal>
+        <literal>SHARE ROW EXCLUSIVE</literal> (<literal>ShareRowExclusiveLock</literal>)
        </term>
        <listitem>
         <para>
@@ -1004,7 +1004,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
 
       <varlistentry>
        <term>
-        <literal>EXCLUSIVE</literal>
+        <literal>EXCLUSIVE</literal> (<literal>ExclusiveLock</literal>)
        </term>
        <listitem>
         <para>
@@ -1026,7 +1026,7 @@ ERROR:  could not serialize access due to read/write dependencies among transact
 
       <varlistentry>
        <term>
-        <literal>ACCESS EXCLUSIVE</literal>
+        <literal>ACCESS EXCLUSIVE</literal> (<literal>AccessExclusiveLock</literal>)
        </term>
        <listitem>
         <para>