RFR: 8317538: RSA have scalability issue for high vCPU numbers

[Vladimir Ivanov]

This patch remove access to the shared variable to fix scalability issue in the multithread environment.  According to testing by the specjvm2008::crypto.rsa the one thread performance reduced for less than 1% while the score for the multithread run increased in ~2x. For the 2 socket system with Xeon 8480+ numbers looks as: 
- 1 thread: 643.15 for original version vs 642.54 for patched one;
- 224 threads: 22446.19 for original vs 46147.41 for patched.

The RSABench microbenchmark reports no score changes for the 1 thread (average for all testcases) and 2.4% improvement for the 224 threads.

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Commit messages:
 - JDK-8317538 RSA have scalability issue for high vCPU numbers

Changes: https://git.openjdk.org/jdk/pull/21622/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21622&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8317538
  Stats: 15 lines in 1 file changed: 0 ins; 14 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/21622.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21622/head:pull/21622

PR: https://git.openjdk.org/jdk/pull/21622