[jdk17u-dev] RFR: 8283710: JVMTI: Use BitSet for object marking

[Roman Kennke]

This is a backport of [JDK-8283710](https://bugs.openjdk.org/browse/JDK-8283710) to 17u.

There have been contextual differences around the declaration of _bitset and corresponding contextual differences in the constructor: the field _dead_objects did not exist in jdk19, but does exist in jdk17u. There also have been differences in the large block that has been removed (the whole of ObjectMarker and related code). Other than that, the backport has been clean and straightforward.

Testing:
 - [x] serviceability/jvmti
 - [x] vmTestbase/nsk/jvmti

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Commit messages:
 - Backport abfd2f98dcbe3e96efe52b1d66e4c2efb3542955

Changes: https://git.openjdk.org/jdk17u-dev/pull/1602/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1602&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8283710
  Stats: 846 lines in 13 files changed: 391 ins; 434 del; 21 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1602.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/1602/head:pull/1602

PR: https://git.openjdk.org/jdk17u-dev/pull/1602