[master] RFR: Lilliput rebase jdk-24+3

[Axel Boldt-Christmas]

Patch queue (#184) rebased on jdk-24+3.

Rebase conflicts / fixes (so far):
 * Rename `HeapRegion` -> `G1HeapRegion`
 * Added SlidingForwarding to parallel full gc (See 3788dcbd02a5fb879ae91e3e5aa1aba8568362d5) 
 * Disabled [JDK-8320448](https://bugs.openjdk.org/browse/JDK-8320448), will require adapting for CompactObjectHeaders (Created [JDK-8334971](https://bugs.openjdk.org/browse/JDK-8334971))
 * Because UseObjectMonitorTable tags all allocations as `mtObjectMonitor` [JDK-8330849](https://bugs.openjdk.org/browse/JDK-8330849) will require some modification.

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Commit messages:
 - Tiny Class-Pointers
 - 8305895: Implementation: JEP 450: Compact Object Headers (Experimental)
 - 8305896: Alternative full GC forwarding
 - 8305898: Alternative self-forwarding mechanism
 - 8315884: New Object to ObjectMonitor mapping
 - Lilliput conf changes for jcheck
 - Merge branch 'lilliput_v6' into lilliput_rebase_target
 - Tiny Class-Pointers
 - 8305895: Implementation: JEP 450: Compact Object Headers (Experimental)
 - 8305896: Alternative full GC forwarding
 - ... and 392 more: https://git.openjdk.org/lilliput/compare/13442745...6fe42912

Changes: https://git.openjdk.org/lilliput/pull/185/files
  Webrev: https://webrevs.openjdk.org/?repo=lilliput&pr=185&range=00
  Stats: 84723 lines in 1918 files changed: 54544 ins; 20945 del; 9234 mod
  Patch: https://git.openjdk.org/lilliput/pull/185.diff
  Fetch: git fetch https://git.openjdk.org/lilliput.git pull/185/head:pull/185

PR: https://git.openjdk.org/lilliput/pull/185