7903806: Enhance jasm/jdis to support value classes and objects

[dansmithcode]

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Some changes to align Valhalla support in asmtools with the latest design for JEP 401.

Latest JVM specification can be found here: https://cr.openjdk.org/~dlsmith/jep401/jep401-20240624/specs/value-objects-jvms.html

I originally made these changes on a custom copy of asmtools, so this was mostly a matter of reviewing my original patch and making updates. There have been some changes, though, and it's quite possible I've missed something.

Some things to be aware of:

• There are no longer any new opcodes or any changes to special methods (like <init>)
• The ACC_IDENTITY flag, which replaces ACC_VALUE, is aliased with ACC_SUPER—this will create some awkwardness until the feature is final. In the mean time, I've had jdis just print super; I imagine someone more experienced with this code might find a clean way to print the right thing based on the version number
• That said, I'm not sure what version number these features will be associated with—spec currently says 67.65535 (i.e., Java 23), but obviously that's going to change
• The Preload attribute, which contained a list of CONSTANT_Classes, has been replaced with LoadableDescriptors, which contains a list of Utf8 descriptor strings
• ACC_PERMITTED_SUBCLASSES and ACC_PRIMITIVE have been abandoned, can be deleted
• The ACC_STRICT flag is now allowed on fields; the spec has some constraints on its use (e.g., the field must be final), but I didn't include those checks, because we have plans to expand the feature to other kinds of fields
• I got this to compile, but I haven't tested anything. Not sure how to run the local tests; I'll do some targeted testing just to make sure the changes basically work.

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Progress

• [x] Change must not contain extraneous whitespace

Issue

• CODETOOLS-7903806: Enhance jasm/jdis to support value classes and objects (Enhancement - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/asmtools.git pull/73/head:pull/73
$ git checkout pull/73

Update a local copy of the PR:
$ git checkout pull/73
$ git pull https://git.openjdk.org/asmtools.git pull/73/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 73

View PR using the GUI difftool:
$ git pr show -t 73

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/asmtools/pull/73.diff

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7903806: Enhance jasm/jdis to support value classes and objects

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• 01: Full - Incremental (f927d5e8)
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