6679: JMC should support project Loom JFR changes

[aymane-harmaz]

This PR :

• adds the virtual attribute to the Thread structure
• makes hashCode and equals use the javaThreadId instead of osThreadId as virtual threads will be attached to the osThreadId = 0

---

• I confirm that I make this contribution in accordance with the OpenJDK Interim AI Policy.

---

Progress

• Commit message must refer to an issue
• Change must be properly reviewed (1 review required, with at least 1 Committer)

Issue

• JMC-6679: JMC should support project Loom JFR changes (New Feature - P2)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jmc.git pull/716/head:pull/716
$ git checkout pull/716

Update a local copy of the PR:
$ git checkout pull/716
$ git pull https://git.openjdk.org/jmc.git pull/716/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 716

View PR using the GUI difftool:
$ git pr show -t 716

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jmc/pull/716.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back aharmaz! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[aymane-harmaz]

/template append

[openjdk]

@aymane-harmaz The pull request template has been appended to the pull request body

[mlbridge]

Webrevs

• 00: Full (bb48fe50)

[thegreystone]

IIRC javaThreadId can be null for native threads that JFR records (GC/VM/JIT threads, etc.). With the new implementation all native threads will be equal to every other native thread. Under the old code, osThreadId distinguished those threads.

[thegreystone]

Also, isVirtual should be in the IMCMethod interface.