RFR: 8339242: Fix overflow issues in AdlArena [v5]

[Casper Norrbin]

On Fri, 6 Sep 2024 08:52:07 GMT, Casper Norrbin <duke at openjdk.org> wrote:

>> Hi everyone,
>> 
>> This PR addresses an issue in `adlArena` where some allocations lack checks for overflow. This could potentially result in successful allocations when called with unrealistic values.
>> 
>> The fix includes:
>> 
>> - Adding assertions to check for potential overflow.
>> - Reordering some operations to guard against overflow.
>
> Casper Norrbin has updated the pull request incrementally with one additional commit since the last revision:
> 
>   assert + static pointer_delta fun

Thank you everyone for the discussion and the reviews.

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PR Comment: https://git.openjdk.org/jdk/pull/20774#issuecomment-2343018081