`IsResizableArrayBuffer` abstract operation now invalid

[Renegade334]

What is the issue with the Web IDL Standard?

At the time that the resizable array buffers proposal was active, the IDL specification used the proposed IsResizableArrayBuffer abstract operation as its predicate for [AllowResizable].

This operation was dropped in the final specification and no longer exists. The inline equivalent is to check for the presence of the [[ArrayBufferMaxByteLength]] internal slot.