Define internal slots of objects directly

Either the object being created is an ordinary object (and follows the
rules for it), or we now specify the internal slots of the exotic
objects.

Addresses part of #655.

index.bs

@@ -78,6 +78,7 @@ urlPrefix: https://tc39.github.io/ecma262/; spec: ECMA-262
         text: Array; url: sec-array-objects
         text: ArrayBuffer; url: sec-arraybuffer-objects
         text: DataView; url: sec-dataview-objects
+        text: Iterator; url: sec-iterator-interface
         text: Map; url: sec-map-objects
         text: Promise; url: sec-promise-objects
         text: Set; url: sec-set-objects
@@ -191,6 +192,7 @@ urlPrefix: https://tc39.github.io/ecma262/; spec: ECMA-262
         url: sec-object-internal-methods-and-internal-slots
             text: internal method
             text: internal slot
+            text: essential internal method
         text: Number type; url: sec-ecmascript-language-types-number-type
         text: Object; for: ECMAScript; url: sec-object-type
         for: ordinary object; url: sec-ordinary-object-internal-methods-and-internal-slots
@@ -6719,17 +6721,6 @@ shall be treated in accordance with the rules for exotic objects.
     {{HTMLAllCollection}} and {{Location}} interfaces. [[HTML]]</span>
 </p>
 
-Unless otherwise specified, exotic objects defined in this section and other specifications have the
-same [=ordinary object/internal slots=] as ordinary objects, and all of the internal methods for
-which alternative definitions are not given are the same as [=ordinary object/internal
-methods|those=] of ordinary objects.
-
-Unless otherwise specified, the \[[Extensible]] internal slot
-of objects defined in this section has the value <emu-val>true</emu-val>.
-
-Unless otherwise specified, the \[[Prototype]] internal slot
-of objects defined in this section is {{%ObjectPrototype%}}.
-
 Unless otherwise specified, the {{ECMAScript/typeof}} operator, when called on an
 exotic object that is not a [=function object=] defined in this section and
 other specifications, must return the string "<code>object</code>".
@@ -10960,11 +10951,12 @@ for that interface on which named properties are exposed.
     1.  If |interface| is declared to inherit from another interface,
         then set |proto| to the [=interface prototype object=] in |realm| for the [=inherited interface=].
     1.  Otherwise, set |proto| to |realm|.\[[Intrinsics]].[[{{%ObjectPrototype%}}]].
-    1.  Let |obj| be a newly created object.
-    1.  Set |obj|'s internal methods to the definitions specified in
+    1.  Let |obj| be a newly created object, with the same internal slots as those of ordinary
+        objects specified in [=ECMA-262 Ordinary object internal methods and internal slots=].
+    1.  Set |obj|'s [=essential internal methods=] to the definitions specified in
         [=ECMA-262 Ordinary object internal methods and internal slots=],
         unless they are specified in the the rest of [[#named-properties-object]].
-    1.  Set |obj|'s remaining internal methods to the definitions specified below.
+    1.  Set |obj|'s remaining [=essential internal methods=] to the definitions specified below.
     1.  Set |obj|.\[[Prototype]] to |proto|.
     1.  Set |obj|.\[[Extensible]] to <emu-val>true</emu-val>.
     1.  Return |obj|.
@@ -11872,12 +11864,16 @@ The value of the [=function object=]’s <code class="idl">name</code> property
 
 A <dfn id="dfn-default-iterator-object" export>default iterator object</dfn> for a given
 [=interface=], target and iteration kind
-is an object whose \[[Prototype]] [=internal slot=] is the
+is an ordinary object that implements the {{Iterator}} ECMAScript interface.
+
+The initial value of the \[[Prototype]] [=internal slot=] of a [=default iterator object=] is the
 [=iterator prototype object=]
 for the [=interface=].
 
-A [=default iterator object=]
-has three internal values:
+The initial value of the \[[Extensible]] [=internal slot=] of a [=default iterator object=] is
+<emu-val>true</emu-val>.
+
+A [=default iterator object=] has three internal values:
 
 1.  its <em>target</em>, which is an object whose values are to be iterated,
 1.  its <em>kind</em>, which is the iteration kind,
@@ -11897,19 +11893,24 @@ class="idl">Object.prototype.toString()</code> is called on a [=default
 iterator object=] of a given [=interface=], the [=class string=] of the
 [=iterator prototype object=] of that [=interface=] is used.
 
+Issue: Define creation of a [=default iterator object=] imperatively instead.
+
 
 <h5 id="es-iterator-prototype-object">Iterator prototype object</h5>
 
 The <dfn id="dfn-iterator-prototype-object" export>iterator prototype object</dfn>
 for a given [=interface=]
-is an object that exists for every interface that has a
+is an ordinary object that exists for every interface that has a
 [=pair iterator=].  It serves as the
 prototype for [=default iterator objects=]
 for the interface.
 
-The \[[Prototype]] [=internal slot=] of an [=iterator prototype object=]
+The initial value of the \[[Prototype]] [=internal slot=] of an [=iterator prototype object=]
 must be {{%IteratorPrototype%}}.
 
+The initial value of the \[[Extensible]] [=internal slot=] of an [=iterator prototype object=]
+must be <emu-val>true</emu-val>.
+
 <div algorithm="to invoke the next property of iterators">
 
     An [=iterator prototype object=] must have a <code class="idl">next</code> data property with attributes
@@ -11961,6 +11962,8 @@ The [=class string=] of an [=iterator prototype object=] for a given [=interface
 is the result of concatenating the [=identifier=] of the [=interface=]
 and the string "<code> Iterator</code>".
 
+Issue: Define creation of an [=iterator prototype object=] imperatively instead.
+
 
 <h4 id="es-maplike">Maplike declarations</h4>
 
@@ -12405,13 +12408,14 @@ the Realm given as an argument.
             1.  Let |targetRealm| be [$GetFunctionRealm$](|newTarget|).
             1.  Set |prototype| to the [=interface prototype object=] for |interface| in
                 |targetRealm|.
-    1.  Let |slots| be « \[[Realm]], \[[PrimaryInterface]] ».
-    1.  Let |instance| be a newly created [=ECMAScript/object=] in |realm|
-        with an internal slot for each name in |slots|.
+    1.  Let |instance| be a newly created [=ECMAScript/object=] in |realm|, with the same internal
+        slots as those of ordinary objects specified in [=ECMA-262 Ordinary object internal
+        methods and internal slots=], as well as \[[Realm]] and \[[PrimaryInterface]].
+    1.  Set |instance|.\[[Prototype]] to |prototype|.
+    1.  Set |instance|.\[[Extensible]] to <emu-val>true</emu-val>.
     1.  Set |instance|.\[[Realm]] to |realm|.
     1.  Set |instance|.\[[PrimaryInterface]] to |interface|.
-    1.  Set |instance|.\[[Prototype]] to |prototype|.
-    1.  Set |instance|'s essential internal methods to the definitions specified in
+    1.  Set |instance|'s [=essential internal methods=] to the definitions specified in
         [=ECMA-262 Ordinary object internal methods and internal slots=].
     1.  Let |interfaces| be the [=inclusive inherited interfaces=] of |interface|.
     1.  [=list/iterate|For every=] [=interface=] |ancestor interface| in |interfaces|: