RFR: 8341513: Remove the unused thread_type field from OSThread [v2]

[Stefan Karlsson]

On Thu, 17 Oct 2024 08:59:43 GMT, Amit Kumar <amitkumar at openjdk.org> wrote:

>> This trivial PR cleans up ` thread_type` field. 
>> 
>> Build is fine on s390x-linux. I have tested on local system Mac-M1 but it failed due to this issue: [JDK-8340341](https://bugs.openjdk.org/browse/JDK-8340341)
>
> Amit Kumar has updated the pull request incrementally with one additional commit since the last revision:
> 
>   revert back SAP's copyright header

Marked as reviewed by stefank (Reviewer).

-------------

PR Review: https://git.openjdk.org/jdk/pull/21532#pullrequestreview-2374726868