[crac] RFR: 8376959: [CRaC] Turn simengine into shared library [v8]

[Radim Vansa]

> Right now `simengine` is implemented as an executable, invoked through `libcrexec` that implements the C/R API. Since the programmatic C/R API should be the main interface, any exec API is redundant; let's turn `simengine` into shared (dynamic) library implementing the API on its own.
> 
> The `pauseengine` does not need to exist on its own; this can be only an option `pause=true` for `simengine`. The implementation is Linux only (and it is out of scope to fill in a non-Linux implementation - the `pause` option can be just excluded in non-Linux `libsimengine`).
> 
> We expect to turn `libcrexec` + `criuengine` into `libcriuengine` in a follow up (not as part of this issue).

Radim Vansa has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains eight commits:

 - Merge branch 'crac' into simengine_separation
 - Fix tests on non-Linux
 - Try fix Windows build
 - Address review comments
 - Fixup
 - Fixups
 - Implement static build & other platforms
 - JDK-8376959: [CRaC] Turn simengine into shared library

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Changes: https://git.openjdk.org/crac/pull/289/files
  Webrev: https://webrevs.openjdk.org/?repo=crac&pr=289&range=07
  Stats: 3003 lines in 27 files changed: 1753 ins; 1172 del; 78 mod
  Patch: https://git.openjdk.org/crac/pull/289.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/289/head:pull/289

PR: https://git.openjdk.org/crac/pull/289