RFR: jdk21: Unit test updated to pass with JDK 21 and above.

[Leonid Kuskov]

On Tue, 25 Feb 2025 22:48:53 GMT, Leonid Kuskov <lkuskov at openjdk.org> wrote:

> Fixed issue caused by switching the build to JDK 21.

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PR Review: https://git.openjdk.org/asmtools/pull/75#pullrequestreview-2642645322