RFR: 8364320: String encodeUTF8 latin1 with negatives [v2]

[Chen Liang]

On Fri, 1 Aug 2025 13:15:29 GMT, Brett Okken <duke at openjdk.org> wrote:

>> As suggested on mailing list, when encoding latin1 bytes to utf-8, we can count the leading positive bytes and in the case where there is a negative, we can copy all the positive values to the target byte[] prior to processing the remaining data 1 byte at a time.
>> 
>> https://mail.openjdk.org/pipermail/core-libs-dev/2025-July/149417.html
>
> Brett Okken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   coding conventions

On second thought, even though Roger's concern is valid, I think the current shape is the best for this code. All usages of `JavaLangAccess.inflateBytesToChars` already exhibit the same pattern as the code here. A separate heuristic for this method would increase our maintenance cost for uncertain gains.

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Marked as reviewed by liach (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/26597#pullrequestreview-3104041492