Whether a SharedArrayBuffer can be allocated here: the global exists and, where a page must be
cross-origin isolated to have it, it is.
Remarks
A capability, not the runtime, so it is decided once at load rather than by a conditional
export: the same browser bundle serves isolated pages, which have it, and pages that do not.
Whether a
SharedArrayBuffercan be allocated here: the global exists and, where a page must be cross-origin isolated to have it, it is.