RFR: 8310996: Add JFR event for connect operations [v4]

[Daniel Fuchs]

On Wed, 6 Nov 2024 00:15:44 GMT, Tim Prinzing <tprinzing at openjdk.org> wrote:

>> Adds a JFR event for socket connect operations.
>> 
>> Existing tests TestSocketEvents and TestSocketChannelEvents modified to also check for connect events.
>
> Tim Prinzing has updated the pull request incrementally with one additional commit since the last revision:
> 
>   suggested changes

The code changes look reasonable to me. I had to re-read the documentation of `finishConnect` to get to that point. I mistakenly thought that this method was reserved for the fully non blocking case. I hadn't realised you could start connect() in non blocking mode and finish it in blocking mode... Thanks @AlanBateman for the thorough review of all these odd cases.

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PR Review: https://git.openjdk.org/jdk/pull/21528#pullrequestreview-2420545416