8380390: Shenandoah: Missing store barrier when resetting bitmaps

[earthling-amzn]

Clean backport. I believe this is a low-risk change that fixes an assertion failure on architectures with weaker memory models than x86 (PowerPC, aarch64).

---

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

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8380390: Shenandoah: Missing store barrier when resetting bitmaps (Bug - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/31518/head:pull/31518
$ git checkout pull/31518

Update a local copy of the PR:
$ git checkout pull/31518
$ git pull https://git.openjdk.org/jdk.git pull/31518/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 31518

View PR using the GUI difftool:
$ git pr show -t 31518

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/31518.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back wkemper! A progress list of the required criteria for merging this PR into jdk27 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.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

@earthling-amzn The following labels will be automatically applied to this pull request:

• hotspot-gc
• shenandoah

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 00: Full (9a005c99)