[crac] RFR: Remove criuengine dependency on libstdc++

[Jan Kratochvil]

Convert it back to plain C. Port the error reporting to plain C.

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Commit messages:
 - Reimplement "Print better diagnostics for spawning CRIU" in plain C
 - Refactorization only - reshuffle code to enable later error reporting
 - Revert "C++ize criuengine"
 - Revert "Print better diagnostics for spawning CRIU"

Changes: https://git.openjdk.org/crac/pull/111/files
 Webrev: https://webrevs.openjdk.org/?repo=crac&pr=111&range=00
  Stats: 990 lines in 3 files changed: 510 ins; 478 del; 2 mod
  Patch: https://git.openjdk.org/crac/pull/111.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/111/head:pull/111

PR: https://git.openjdk.org/crac/pull/111