Change locktype "speculative token" to "spectoken".

It's just weird that this name wasn't chosen to look like an
identifier.  The suspicion that it wasn't thought about too
hard is reinforced by the fact that it wasn't documented in
the pg_locks view (until I did so, a day or two back).

Update, and add a comment reminding future adjusters of this
array to fix the docs too.

Do some desultory wordsmithing on various entries in the wait
events tables.

Discussion: https://postgr.es/m/24595.1589326879@sss.pgh.pa.us

doc/src/sgml/catalogs.sgml

@@ -10238,7 +10238,7 @@ SCRAM-SHA-256$<replaceable>&lt;iteration count&gt;</replaceable>:<replaceable>&l
        <literal>tuple</literal>,
        <literal>transactionid</literal>,
        <literal>virtualxid</literal>,
-       <literal>speculative token</literal>,
+       <literal>spectoken</literal>,
        <literal>object</literal>,
        <literal>userlock</literal>, or
        <literal>advisory</literal>.

src/backend/utils/adt/lockfuncs.c

@@ -22,7 +22,10 @@
 #include "utils/builtins.h"
 
 
-/* This must match enum LockTagType! */
+/*
+ * This must match enum LockTagType!  Also, be sure to document any changes
+ * in the docs for the pg_locks view and for wait event types.
+ */
 const char *const LockTagTypeNames[] = {
 	"relation",
 	"extend",
@@ -30,7 +33,7 @@ const char *const LockTagTypeNames[] = {
 	"tuple",
 	"transactionid",
 	"virtualxid",
-	"speculative token",
+	"spectoken",
 	"object",
 	"userlock",
 	"advisory"

src/test/isolation/expected/insert-conflict-specconflict.out

@@ -362,16 +362,16 @@ step controller_print_speculative_locks:
     SELECT pa.application_name, locktype, mode, granted
     FROM pg_locks pl JOIN pg_stat_activity pa USING (pid)
     WHERE
-        locktype IN ('speculative token', 'transactionid')
+        locktype IN ('spectoken', 'transactionid')
         AND pa.datname = current_database()
         AND pa.application_name LIKE 'isolation/insert-conflict-specconflict-s%'
     ORDER BY 1, 2, 3, 4;
 
 application_namelocktype       mode           granted        
 
-isolation/insert-conflict-specconflict-s1speculative tokenShareLock      f              
+isolation/insert-conflict-specconflict-s1spectoken      ShareLock      f              
 isolation/insert-conflict-specconflict-s1transactionid  ExclusiveLock  t              
-isolation/insert-conflict-specconflict-s2speculative tokenExclusiveLock  t              
+isolation/insert-conflict-specconflict-s2spectoken      ExclusiveLock  t              
 isolation/insert-conflict-specconflict-s2transactionid  ExclusiveLock  t              
 step controller_unlock_2_4: SELECT pg_advisory_unlock(2, 4);
 pg_advisory_unlock
@@ -384,7 +384,7 @@ step controller_print_speculative_locks:
     SELECT pa.application_name, locktype, mode, granted
     FROM pg_locks pl JOIN pg_stat_activity pa USING (pid)
     WHERE
-        locktype IN ('speculative token', 'transactionid')
+        locktype IN ('spectoken', 'transactionid')
         AND pa.datname = current_database()
         AND pa.application_name LIKE 'isolation/insert-conflict-specconflict-s%'
     ORDER BY 1, 2, 3, 4;
@@ -406,7 +406,7 @@ step controller_print_speculative_locks:
     SELECT pa.application_name, locktype, mode, granted
     FROM pg_locks pl JOIN pg_stat_activity pa USING (pid)
     WHERE
-        locktype IN ('speculative token', 'transactionid')
+        locktype IN ('spectoken', 'transactionid')
         AND pa.datname = current_database()
         AND pa.application_name LIKE 'isolation/insert-conflict-specconflict-s%'
     ORDER BY 1, 2, 3, 4;

src/test/isolation/specs/insert-conflict-specconflict.spec

@@ -64,7 +64,7 @@ step "controller_print_speculative_locks" {
     SELECT pa.application_name, locktype, mode, granted
     FROM pg_locks pl JOIN pg_stat_activity pa USING (pid)
     WHERE
-        locktype IN ('speculative token', 'transactionid')
+        locktype IN ('spectoken', 'transactionid')
         AND pa.datname = current_database()
         AND pa.application_name LIKE 'isolation/insert-conflict-specconflict-s%'
     ORDER BY 1, 2, 3, 4;