This PR proposes improving performance for two `VarHandle` objects and increasing the timeout for the tests. The size of a mapped file is also reduced from 3 GiB to 2.5 GiB. This still crosses the 2<sup> 31</sup> boundary.
------------- Commit messages: - Improve performance and increase timeout Changes: https://git.openjdk.org/jdk/pull/15326/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15326&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8314071 Stats: 12 lines in 1 file changed: 0 ins; 0 del; 12 mod Patch: https://git.openjdk.org/jdk/pull/15326.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/15326/head:pull/15326 PR: https://git.openjdk.org/jdk/pull/15326
