8x "unknown" -> "an Iterator Record"

See tc39#2591 (review)

spec.html

@@ -9608,7 +9608,7 @@ <h1>
  <emu-clause id="sec-runtime-semantics-iteratorbindinginitialization" oldids="sec-destructuring-binding-patterns-runtime-semantics-iteratorbindinginitialization,sec-function-definitions-runtime-semantics-iteratorbindinginitialization,sec-arrow-function-definitions-runtime-semantics-iteratorbindinginitialization,sec-async-arrow-function-definitions-IteratorBindingInitialization" type="sdo">
  <h1>
  Runtime Semantics: IteratorBindingInitialization (
- _iteratorRecord_: unknown,
+ _iteratorRecord_: an Iterator Record,
  _environment_: unknown,
  ): either a normal completion containing ~unused~ or an abrupt completion
  </h1>
@@ -20815,7 +20815,7 @@ <h1>
  <emu-clause id="sec-runtime-semantics-iteratordestructuringassignmentevaluation" type="sdo">
  <h1>
  Runtime Semantics: IteratorDestructuringAssignmentEvaluation (
- _iteratorRecord_: unknown,
+ _iteratorRecord_: an Iterator Record,
  ): either a normal completion containing ~unused~ or an abrupt completion
  </h1>
  <dl class="header">
@@ -22084,7 +22084,7 @@ <h1>
  ForIn/OfBodyEvaluation (
  _lhs_: a Parse Node,
  _stmt_: a |Statement| Parse Node,
- _iteratorRecord_: unknown,
+ _iteratorRecord_: an Iterator Record,
  _iterationKind_: unknown,
  _lhsKind_: ~assignment~, ~varBinding~, or ~lexicalBinding~,
  _labelSet_: a List of Strings,
@@ -43181,7 +43181,7 @@ <h1>Async-from-Sync Iterator Objects</h1>
  <emu-clause id="sec-createasyncfromsynciterator" type="abstract operation">
  <h1>
  CreateAsyncFromSyncIterator (
- _syncIteratorRecord_: unknown,
+ _syncIteratorRecord_: an Iterator Record,
  ): an Iterator Record
  </h1>
  <dl class="header">
@@ -43857,7 +43857,7 @@ <h1>
  <emu-clause id="sec-performpromiseall" type="abstract operation">
  <h1>
  PerformPromiseAll (
- _iteratorRecord_: unknown,
+ _iteratorRecord_: an Iterator Record,
  _constructor_: a constructor,
  _resultCapability_: a PromiseCapability Record,
  _promiseResolve_: a function object,
@@ -43945,7 +43945,7 @@ <h1>Promise.allSettled ( _iterable_ )</h1>
  <emu-clause id="sec-performpromiseallsettled" type="abstract operation">
  <h1>
  PerformPromiseAllSettled (
- _iteratorRecord_: unknown,
+ _iteratorRecord_: an Iterator Record,
  _constructor_: a constructor,
  _resultCapability_: a PromiseCapability Record,
  _promiseResolve_: a function object,
@@ -44072,7 +44072,7 @@ <h1>Promise.any ( _iterable_ )</h1>
  <emu-clause id="sec-performpromiseany" type="abstract operation">
  <h1>
  PerformPromiseAny (
- _iteratorRecord_: unknown,
+ _iteratorRecord_: an Iterator Record,
  _constructor_: a constructor,
  _resultCapability_: a PromiseCapability Record,
  _promiseResolve_: a function object,
@@ -44171,7 +44171,7 @@ <h1>Promise.race ( _iterable_ )</h1>
  <emu-clause id="sec-performpromiserace" type="abstract operation">
  <h1>
  PerformPromiseRace (
- _iteratorRecord_: unknown,
+ _iteratorRecord_: an Iterator Record,
  _constructor_: a constructor,
  _resultCapability_: a PromiseCapability Record,
  _promiseResolve_: a function object,