RFR: 8308286 Fix clang warnings in linux code

[Phil Race]

On Wed, 17 May 2023 12:28:47 GMT, Artem Semenov <asemenov at openjdk.org> wrote:

> When using the clang compiler to build OpenJDk on Linux, we encounter various "warnings as errors".
> They can be fixed with small changes.

I don't like this approach at all. if github had a "reject" button I'd be pushing it now.
updating the makefiles is the normal way to do this but I don't know if we even want that.
Until clang is the supported compiler for Linux then I see no reason for this to be in JDK at all.

Code changes which make it so there's no warning would be the preferred way but I'd expect that to be tested properly. Also if the warning is spurious - sometimes they are - then that would NOT be appropriate.

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Changes requested by prr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/14033#pullrequestreview-1437172390