ICU-22392 Add, primary support for Haiku

[Begasus]

Checklist

• [x] Required: Issue filed: https://unicode-org.atlassian.net/browse/ICU-22392
• [x] Required: The PR title must be prefixed with a JIRA Issue number.
• [x] Required: The PR description must include the link to the Jira Issue, for example by completing the URL in the first checklist item
• [ ] Required: Each commit message must be prefixed with a JIRA Issue number.
• [ ] Issue accepted (done by Technical Committee after discussion)
• [ ] Tests included, if applicable
• [ ] API docs and/or User Guide docs changed or added, if applicable

[CLAassistant]

All committers have signed the CLA.

[jira-pull-request-webhook[bot]]

Notice: the branch changed across the force-push!

• icu4c/source/common/putilimp.h is different

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~ Your Friendly Jira-GitHub PR Checker Bot

[jira-pull-request-webhook[bot]]

Notice: the branch changed across the force-push!

• icu4c/source/common/putilimp.h is different

View Diff Across Force-Push

~ Your Friendly Jira-GitHub PR Checker Bot

[jira-pull-request-webhook[bot]]

Hooray! The files in the branch are the same across the force-push. 😃

~ Your Friendly Jira-GitHub PR Checker Bot

[Begasus]

Saw this was still open anything left to do?