RFR: 7903806: Enhance jasm/jdis to support value classes and objects [v2]

[Dan Smith]

> 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 I originally made these changes on a custom copy of asmtools, so this was mostly a matter of reviewing my original patch and making updates.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.

Dan Smith has updated the pull request incrementally with one additional commit since the last revision:

  Fix printing of inner class identity flag

-------------

Changes:
  - all: https://git.openjdk.org/asmtools/pull/73/files
  - new: https://git.openjdk.org/asmtools/pull/73/files/aef02298..f927d5e8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=asmtools&pr=73&range=01
 - incr: https://webrevs.openjdk.org/?repo=asmtools&pr=73&range=00-01

  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/asmtools/pull/73.diff
  Fetch: git fetch https://git.openjdk.org/asmtools.git pull/73/head:pull/73

PR: https://git.openjdk.org/asmtools/pull/73