RFR: 8342041: Test gc/shenandoah/oom/TestClassLoaderLeak.java slow on Windows after JDK-8340490 [v2]

[Xiaolong Peng]

> Fixing the regression on Windows caused by JDK-8340490, the bug is actually caused by different behavior in `os:: os::elapsed_counter()` which I wasn't aware of.  Windows doesn't have nanosecond hi-res clock support, so instead of nanoseconds it returns the the current value of the performance counter([link](https://learn.microsoft.com/en-us/windows/win32/api/profileapi/nf-profileapi-queryperformancecounter)).
> 
> Some additional changes are also included in the PR for better performance and throughput. 
> 
> ### Tests
>  - [x] Verify gc/shenandoah/oom/TestClassLoaderLeak.java on Windows, no regression at all(improved slightly by ~1s comparing to original impl) 
>  - [x] Run test suites hotspot_gc_shenandoah with linux-aarch64-server-fastdebug

Xiaolong Peng has updated the pull request incrementally with one additional commit since the last revision:

  Revert "8342044: Increase timeout of gc/shenandoah/oom/TestClassLoaderLeak.java"
  
  This reverts commit 2c0c65353b2f67bdcd954b4d2c2ae3e9b24d1c22.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/22172/files
  - new: https://git.openjdk.org/jdk/pull/22172/files/64751d8f..d83dfbd4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22172&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22172&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/22172.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22172/head:pull/22172

PR: https://git.openjdk.org/jdk/pull/22172