RFR: 8302838: jabswitch main() should avoid calling exit explicitly

[SWinxy]

On Mon, 20 Feb 2023 08:10:54 GMT, Julian Waters <jwaters at openjdk.org> wrote:

> In jabswitch, main is defined as `void main()`, which requires an explicit exit call whenever an error occurs, and extra error checking code on our part. Visual C++ will automatically convert all instances of `void main()` to return 0 in all cases anyway, and there isn't anything gained from using this custom signature when the same can be achieved by simply returning the error value normally, so I propose we simply change it to the regular `int main` signature

Marked as reviewed by SWinxy at github.com (no known OpenJDK username).

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

PR: https://git.openjdk.org/jdk/pull/12650