[master] RFR: 8300527: [Lilliput] Simplify and optimize loading of Klass*

[Roman Kennke]

With the new fast-locking, we can greatly simplify the loading of the Klass* from an object. We no longer have to call into the runtime to ensure that the header is changed under our feet (by installing the INFLATION marker). Instead, we can do a simple check for the object being monitor-locked, and safely load the displaced header, if that is the case.

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Commit messages:
 - Add missing includes
 - Fix merge error
 - Merge branch 'master' into JDK-8300527
 - 8300527: [Lilliput] Simplify and optimize loading of Klass*
 - Fix/revert Shenandoah forwarding protocol to not use INFLATING 2-step
 - Merge branch 'master' into JDK-8300733
 - [Lilliput] Enable fast-locking for Lilliput

Changes: https://git.openjdk.org/lilliput/pull/66/files
 Webrev: https://webrevs.openjdk.org/?repo=lilliput&pr=66&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8300527
  Stats: 390 lines in 28 files changed: 76 ins; 279 del; 35 mod
  Patch: https://git.openjdk.org/lilliput/pull/66.diff
  Fetch: git fetch https://git.openjdk.org/lilliput pull/66/head:pull/66

PR: https://git.openjdk.org/lilliput/pull/66