8351268: [JVMCI] Enhance JVMCI by leveraging modern Java features

[mur47x111]

Return unmodifiable list instead of new arrays.

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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-8351268: [JVMCI] Enhance JVMCI by leveraging modern Java features (Enhancement - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/25442/head:pull/25442
$ git checkout pull/25442

Update a local copy of the PR:
$ git checkout pull/25442
$ git pull https://git.openjdk.org/jdk.git pull/25442/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 25442

View PR using the GUI difftool:
$ git pr show -t 25442

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/25442.diff

[bridgekeeper]

👋 Welcome back yzheng! 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.

[openjdk]

@mur47x111 The following labels will be automatically applied to this pull request:

• graal
• hotspot-compiler

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[dougxc]

Please try come up with a jtreg test that prevents introduction of new JVMCI methods returning arrays. Some kind of white list approach is probably best.

[dougxc]

mutable array -> mutable list

[openjdk]

@mur47x111 this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout JDK-8351268
git fetch https://git.openjdk.org/jdk.git master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push