"Convert a value to a key" should return invalid for detached array buffers (#440)

Closes #417 by updating "7.4 Convert a value to a key" to return invalid when the input buffer source is detached.

Author: SteveBeckerMSFT

index.bs

@@ -6366,9 +6366,11 @@ steps may throw an exception.
       <!-- Binary -->
       : If |input| is a [=buffer source type=]
       ::
+          1. If |input| is [[=BufferSource/detached=]] then return invalid.
+
           1. Let |bytes| be the result of
               [=/get a copy of the buffer source|getting a copy of the bytes held by the buffer source=]
-              |input|. Rethrow any exceptions.
+              |input|.
 
           1. Return a new [=/key=] with [=key/type=]
               *binary* and [=key/value=] |bytes|.
@@ -6717,6 +6719,7 @@ For the revision history of the second edition, see [that document's Revision Hi
 * Used [[infra]]'s list sorting definition. (<#346>)
 * Added a definition for [=transaction/live=] transactions, and renamed "run an upgrade transaction" to [=/upgrade a database=], to disambiguate "running". (<#408>)
 * Specified the {{DOMException}} type for failures when reading a value from the underlying storage in [[#object-store-retrieval-operation]]. (<#423>)
+* Updated [=convert a value to a key=] to return invalid for detached array buffers. (<#417>)
 
 <!-- ============================================================ -->
 # Acknowledgements # {#acknowledgements}
@@ -6787,6 +6790,7 @@ Pablo Castro,
 Philip Jägenstedt,
 Shawn Wilsher,
 Simon Pieters,
+Steve Becker,
 Tobie Langel,
 Victor Costan,
 Xiaoqian Wu,