[crac] RFR: 8364554: [CRaC] Improve CRaC VM options' docs [v4]

[Timofei Pushkin]

On Tue, 5 Aug 2025 09:44:35 GMT, Timofei Pushkin <tpushkin at openjdk.org> wrote:

>> Besides some wording and formatting of VM options:
>> - Renames `CRaCAllowToSkipCheckpoint` to `CRaCSkipCheckpoint` since it makes the VM always skip checkpoints and not only in some cases
>> - Replaces `CRaCMaxHeapSizeBeforeCheckpoint == 0` with `FLAG_IS_DEFAULT(CRaCMaxHeapSizeBeforeCheckpoint)` because the docs 0 do not specify 0 as a special value
>
> Timofei Pushkin has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix CRaCSkipCheckpoint aliasing

src/hotspot/share/runtime/arguments.cpp line 1:

> 1: /*

BTW maybe it is time to put expiration dates for all of CRaC's deprecated/obsoleted options? Almost all of them are aliases and having aliases slows down argument parsing: for each parsed argument there is a linear search through the list of aliases to try to find the real name.

Since most of them have been deprecated since winter we can put 26 as the expiration version: it will be more a year since the options were deprecated. For the ones deprecated/obsoleted today it can be 27.

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PR Review Comment: https://git.openjdk.org/crac/pull/256#discussion_r2253780936