RFR: 8332252: Clean up vmTestbase/vm/share

[Leonid Mesnik]

The vmTestbase/vm/share is a shared test library for vmTestbase tests. This library contains a lot of code that is used by only by small number of tests or not used at all. There are no plans to actively develop new tests in vmTestsbase and improve this shared library. 
The final goal of this and the following PRs is to reduce the maintenance cost of vmTestbase by eliminating this library.

Also, this PR moves test-specific code into corresponding test directories to increase code locality. This allows later easier move tests from vmTestbase.

The few remaining classes include 
InMemoryJavaCompiler.java
that is very similar to same class from the standard testlibrary and could be merge with it and
ProcessUtils.java
which is used by
test/hotspot/jtreg/runtime/Thread/TestBreakSignalThreadDump.java
and thus should be moved into the standard testlibrary.
The stack and options might be merged in nsk/share test library.

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Commit messages:
 - 8332252: Clean up vmTestbase/vm/share

Changes: https://git.openjdk.org/jdk/pull/19727/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19727&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8332252
  Stats: 1647 lines in 44 files changed: 17 ins; 1586 del; 44 mod
  Patch: https://git.openjdk.org/jdk/pull/19727.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19727/head:pull/19727

PR: https://git.openjdk.org/jdk/pull/19727