RFR: 8295792: Clean up old async close code

[Alan Bateman]

On Fri, 21 Oct 2022 14:28:02 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

> Please review this PR that removes the remains of old fdTable-based socket close synchronization.
> 
> Verified that tier1-3 tests continue to pass on Linux, MacOS and Windows. Did not verify AIX.
> 
> Also removed one slow test for an issue in fdtable implementation; as far as I could tell, it is no longer relevant.

Good cleanup. At some point I think we should put error handling into NET_Wait but not here.

-------------

Marked as reviewed by alanb (Reviewer).

PR: https://git.openjdk.org/jdk/pull/10816