RFR: 8318127: align_up has potential overflow [v3]

[Kim Barrett]

On Tue, 1 Oct 2024 14:39:10 GMT, Casper Norrbin <cnorrbin at openjdk.org> wrote:

>> Hi everyone,
>> 
>> The `align_up` function contained code which could potentially overflow and produce an incorrect result. This PR adds an assert to check for such.
>> 
>> Additionally, two test case that previously caused an overflow have been updated to use the highest possible values that do not trigger an overflow.
>
> Casper Norrbin has refreshed the contents of this pull request, and previous commits have been removed. Incremental views are not available. The pull request now contains two commits:
> 
>  - change reserve_memory test
>  - align overflow check

Add at least one death test (TEST_VM_ASSERT) for align_up hitting the assertion.

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Changes requested by kbarrett (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20808#pullrequestreview-2341029473