RFR: 8347840: Fix testlibrary compilation warnings

[Alan Bateman]

On Wed, 15 Jan 2025 23:48:33 GMT, Leonid Mesnik <lmesnik at openjdk.org> wrote:

> There few compiler warning disabled in the testlibary build.
> They should be fixed or localized and removed from build to prevent new possible issues.
> 
> The main goal is to avoid new such issues in the testlibrary. 
> Tested with tier1-5 to ensure that all tests were passed.

test/lib/jdk/test/lib/thread/VThreadPinner.java line 97:

> 95:      * virtual thread then it invokes the task directly.
> 96:      */
> 97:     @SuppressWarnings("unchecked")

If you change the code to the follow, same in VThreadRunner then it would avoid the the SW on the method and avoid the other change you have to VThreadRunner.

            @SuppressWarnings("unchecked")
            var x = (X) ex;
            throw x;

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PR Review Comment: https://git.openjdk.org/jdk/pull/23143#discussion_r1917853893