RFR: JDK-8313670: Simplify shared lib name handling code in some tests [v2]

[Matthias Baesken]

> There is coding e.g. in
> https://github.com/openjdk/jdk/blob/master/test/jdk/jdk/jfr/event/runtime/TestNativeLibrariesEvent.java#L72
> that deals with shared lib naming on different OS.
> This code should be simplified.

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  use Platform.sharedLibraryPrefix in more tests

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/15151/files
  - new: https://git.openjdk.org/jdk/pull/15151/files/c99d984d..e708bb68

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15151&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15151&range=00-01

  Stats: 9 lines in 3 files changed: 0 ins; 4 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/15151.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15151/head:pull/15151

PR: https://git.openjdk.org/jdk/pull/15151