Eliminate use of unsafe in StringSupport #8507
Description
The following error shows up now when running with JDK 25 builds:
WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
WARNING: sun.misc.Unsafe::arrayBaseOffset has been called by org.jruby.util.StringSupport (file:/home/headius/work/jruby/lib/jruby.jar)
WARNING: Please consider reporting this to the maintainers of class org.jruby.util.StringSupport
WARNING: sun.misc.Unsafe::arrayBaseOffset will be removed in a future releas
We should replace this usage with something like VarHandle in JRuby 10, and consider options for avoiding this warning on 9.4 maintenance releases.