8374147: [lworld] Cleanup markword bit masks and constants

[caspernorrbin]

Hi everyone,

The current naming of the Valhalla-related markWord definitions is a bit confusing and does not really match the mainline naming scheme. In particular, the new *_mask_in_place constants are not just the corresponding *_mask shifted into place. They are instead used as classification masks, so they also include either lock bits or other Valhalla bits.

In this change I tried to make the structure and naming more regular, closer to the pattern we already use in mainline, and also closer to how the non-Valhalla bits are laid out here.

I split the definitions into a clearer flow:

• Added *_mask for all Valhalla fields.
• Kept *_mask_in_place for the Valhalla fields, but as the shifted version of each corresponding mask.
• Added new *_pattern_mask constants for the composite masks, to make it clearer that these represent more than a single field mask. This also matches the existing *_pattern naming better.

As part of this, I updated all uses to the new names that match the intended naming. Overall, this gives the markWord bit definitions a more consistent and easier to follow structure.

Testing:

• Tiers 1-3

---

Progress

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Issue

• JDK-8374147: [lworld] Cleanup markword bit masks and constants (Enhancement - P4)

Reviewing

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$ git pull https://git.openjdk.org/valhalla.git pull/2238/head

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