RFR: 8357920: Add .rej and .orig to .gitignore

[SendaoYan]

On Tue, 27 May 2025 21:59:05 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

> The file types .rej and .orig are often created by diff tools. Adding them to .gitignore will help people from mistakenly committing these files.
> 
> See https://github.com/openjdk/jdk/pull/25306#discussion_r2102407122 for an example of where this happened.

LGTM

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Marked as reviewed by syan (Committer).

PR Review: https://git.openjdk.org/jdk/pull/25474#pullrequestreview-2875182457