RFR: 8337168: Optimize LocalDateTime.toString [v4]

[Stephen Colebourne]

On Thu, 25 Jul 2024 23:05:46 GMT, Shaojin Wen <duke at openjdk.org> wrote:

>> The current LocalDateTime.toString implementation concatenates the toString results of date and time, which can be passed to StringBuilder to reduce additional object allocation and improve performance.
>
> Shaojin Wen has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/java.base/share/classes/java/time/LocalTime.java
>   
>   Co-authored-by: Chen Liang <liach at openjdk.org>

This change is fine, however the comments and performance testing assume that a date is always 10 characters long which isn't true, as the year could be greater than 9999.

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PR Review: https://git.openjdk.org/jdk/pull/20321#pullrequestreview-2201711797