RFR: 8339531: Improve performance of MemorySegment::mismatch [v12]

[Per Minborg]

On Thu, 12 Sep 2024 10:54:47 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> This PR proposes to improve the performance of `MemorySegment::mismatch` by using Java code rather than transitioning to native code.
>
> Per Minborg has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Fix yet another typo
>  - Fix typo

Here are some other benchmarks:

![image](https://github.com/user-attachments/assets/d6d0ef15-d768-4424-9dad-cbe43c139094)

![image](https://github.com/user-attachments/assets/8cbce3cd-0bff-4276-ab51-041c787e1bab)

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

PR Comment: https://git.openjdk.org/jdk/pull/20848#issuecomment-2346040710