8338867: GenShen: Do all size accounting in words

[kdnilsen]

Draft while I work through the details of this

We want to consistently do all size accounting in words rather than a mix of bytes and words. This will affect both traditional Shenandoah and Generational Shenandoah implementations.

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Progress

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

Issue

• JDK-8338867: GenShen: Do all size accounting in words (Enhancement - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/shenandoah.git pull/482/head:pull/482
$ git checkout pull/482

Update a local copy of the PR:
$ git checkout pull/482
$ git pull https://git.openjdk.org/shenandoah.git pull/482/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 482

View PR using the GUI difftool:
$ git pr show -t 482

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/shenandoah/pull/482.diff

[bridgekeeper]

👋 Welcome back kdnilsen! 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]

@kdnilsen 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 do-all-size-accounting-in-words
git fetch https://git.openjdk.org/shenandoah.git master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push