isl: built-in 104 is request_next -- named from the game's own log string

Followed the writer, not the reader.  [phase+10160]'s only writer in
the image is one site in the mission frame loop sub_821AA1B0: it does
obj->get() on an object fetched from a registry by id 0x20FFFF02,
stores it to the phase, then clears the object -- read, publish, clear,
every frame.

The id namespace has exactly three members (0x20FFFF00/01/02), each
built at exactly 4 sites, and two of those are in sub_821D5178, which
gets 0x20FFFF01 and 0x20FFFF02 and logs both:

  GamePart_ReadyRoom::Impl::OnCommand - Wait() command is requested.
  Check flow control valiables. WAIT_MODE : %d, REQUEST_NEXT : %d

Argument order gives 0x20FFFF01 = WAIT_MODE, 0x20FFFF02 = REQUEST_NEXT.
PrepareScript corroborates: it sets WAIT_MODE=1, REQUEST_NEXT=0 before
an ISL script runs.  So the six tutorial stages' lone dominating
condition request_next() != 1 is the script waiting on the game part's
proceed flag.

6 artefact lines changed, all 6 pair exactly.

docs/re/data/isl-phase-guards-all.txt

@@ -1131,7 +1131,7 @@ An exit with no TRIGGER is not fired by a branch — a timeout exit is
 fired by time passing, which is not a property of the graph.
 
 ## phase 1 — END_PHASE at 0x002958: 1 necessary condition(s)
-    precond  0x002898  builtin104() != 1
+    precond  0x002898  request_next() != 1
 
 ------------------------------------------------------------------------
 
@@ -1152,7 +1152,7 @@ An exit with no TRIGGER is not fired by a branch — a timeout exit is
 fired by time passing, which is not a property of the graph.
 
 ## phase 1 — END_PHASE at 0x001950: 1 necessary condition(s)
-    precond  0x001890  builtin104() != 1
+    precond  0x001890  request_next() != 1
 
 ------------------------------------------------------------------------
 
@@ -1173,7 +1173,7 @@ An exit with no TRIGGER is not fired by a branch — a timeout exit is
 fired by time passing, which is not a property of the graph.
 
 ## phase 1 — END_PHASE at 0x00261C: 1 necessary condition(s)
-    precond  0x00255C  builtin104() != 1
+    precond  0x00255C  request_next() != 1
 
 ------------------------------------------------------------------------
 
@@ -1194,7 +1194,7 @@ An exit with no TRIGGER is not fired by a branch — a timeout exit is
 fired by time passing, which is not a property of the graph.
 
 ## phase 1 — END_PHASE at 0x001250: 1 necessary condition(s)
-    precond  0x001190  builtin104() != 1
+    precond  0x001190  request_next() != 1
 
 ------------------------------------------------------------------------
 
@@ -1215,7 +1215,7 @@ An exit with no TRIGGER is not fired by a branch — a timeout exit is
 fired by time passing, which is not a property of the graph.
 
 ## phase 1 — END_PHASE at 0x00208C: 1 necessary condition(s)
-    precond  0x001FCC  builtin104() != 1
+    precond  0x001FCC  request_next() != 1
 
 ------------------------------------------------------------------------
 
@@ -1236,7 +1236,7 @@ An exit with no TRIGGER is not fired by a branch — a timeout exit is
 fired by time passing, which is not a property of the graph.
 
 ## phase 1 — END_PHASE at 0x001208: 1 necessary condition(s)
-    precond  0x001148  builtin104() != 1
+    precond  0x001148  request_next() != 1
 
 ------------------------------------------------------------------------