[crac] RFR: Refactoring - extracted crac files [v2]

[Roman Marchenko]

> CRaC-related functionality is moved to `crac*.hpp/cpp` files, and now it is in `crac` class instead of `os`.

Roman Marchenko has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - Merge branch 'crac' into crac-extract
 - Getting rid of crac::Linux
 - Removing trailing spaces
 - Refactoring - extracted crac* files

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

Changes:
  - all: https://git.openjdk.org/crac/pull/84/files
  - new: https://git.openjdk.org/crac/pull/84/files/7b169d95..e3c180f7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=crac&pr=84&range=01
 - incr: https://webrevs.openjdk.org/?repo=crac&pr=84&range=00-01

  Stats: 64 lines in 8 files changed: 9 ins; 39 del; 16 mod
  Patch: https://git.openjdk.org/crac/pull/84.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/84/head:pull/84

PR: https://git.openjdk.org/crac/pull/84