Check for isTransferring slot presence

Author: youennf

index.bs

@@ -6392,7 +6392,7 @@ for="value-with-size">value</dfn> and <dfn for="value-with-size">size</dfn>.
  1. If ! [$IsNonNegativeNumber$](|size|) is false, throw a {{RangeError}} exception.
  1. If |size| is +∞, throw a {{RangeError}} exception.
  1. Let |enqueuedValue| be |value|.
- 1. If |container|.\[[isTransferring]] is true, perform the following steps:
+ 1. If |container| has a \[[isTransferring]] internal slot whose value is true, perform the following steps:
     1. Set |enqueuedValue| to [$StructuredTransferOrClone$](|value|, |transferList|).
     1. If |enqueuedValue| is an abrupt completion, return.
  1. [=list/Append=] a new [=value-with-size=] with [=value-with-size/value=] |enqueuedValue| and
@@ -6415,7 +6415,7 @@ for="value-with-size">value</dfn> and <dfn for="value-with-size">size</dfn>.
  performs the following steps:
 
  1. Assert: |container| has \[[queue]] and \[[queueTotalSize]] internal slots.
- 1. If |container|.\[[isTransferring]] is true, perform the following steps until |container|.\[[queue]]
+ 1. If |container| has a \[[isTransferring]] internal slot whose value is true, perform the following steps until |container|.\[[queue]]
     is [=list/is empty|empty=]:
     1. Let |chunk| be ! [$DequeueValue$]([=this=]).
     1. If |chunk| has [=closing steps=], perform the [=closing steps=] given |chunk|.