RFR: 8316325: [lw5] sync javac with the current JVMS, particularly assertions on new class attributes [v2]

[Vicente Romero]

> This PR is implementing assertions on new classfile attributes, see [1]
> 
> [1] https://cr.openjdk.org/~dlsmith/jep401/jep401-20230519/specs/flattened-heap-jvms.html

Vicente Romero has updated the pull request incrementally with one additional commit since the last revision:

  adding new line at the end of file

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/927/files
  - new: https://git.openjdk.org/valhalla/pull/927/files/f58c3c3e..a29389be

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=927&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=927&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/valhalla/pull/927.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/927/head:pull/927

PR: https://git.openjdk.org/valhalla/pull/927