[crac] RFR: Do not register MethodHandleNatives

[Anton Kozlov]

A simple solution for the lambda problem in the CRaC Core: do not register CALL_SITES at all.

A second part of the PR introduces an interface for Cleaner.register() with priority parameter.

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Commit messages:
 - Use internal interfaces for registration
 - Do not register MethodHandleNatives

Changes: https://git.openjdk.org/crac/pull/76/files
 Webrev: https://webrevs.openjdk.org/?repo=crac&pr=76&range=00
  Stats: 39 lines in 6 files changed: 28 ins; 8 del; 3 mod
  Patch: https://git.openjdk.org/crac/pull/76.diff
  Fetch: git fetch https://git.openjdk.org/crac.git pull/76/head:pull/76

PR: https://git.openjdk.org/crac/pull/76