RFR: 8337168: Optimize LocalDateTime.toString

[Chen Liang]

On Thu, 25 Jul 2024 05:06:17 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.

Simple and straightforward improvement.

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Marked as reviewed by liach (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/20321#pullrequestreview-2198838834