RFR: 8334599: Improve code from JDK-8302671

[Julian Waters]

In [JDK-8302671](https://bugs.openjdk.org/browse/JDK-8302671) I fixed a memmove decay bug by rewriting a sizeof on an array to an explicit size of 256, but this is a bit of a band aid fix. It's come to my attention that in C++, one can pass an array by reference, which causes sizeof to work correctly on an array and has the added bonus of enforcing an array of that size on the arguments passed to that method. I've reverted my change from 8302671 and instead explicitly made kstate an array reference so that sizeof works on the array as expected, and that the array size can be explicitly set in the array brackets

Verification: https://godbolt.org/z/Ezj76eWWY and GitHub Actions

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Commit messages:
 - 8334599

Changes: https://git.openjdk.org/jdk/pull/19798/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19798&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334599
  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/19798.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19798/head:pull/19798

PR: https://git.openjdk.org/jdk/pull/19798