[lworld] RFR: 8249869: [lworld] Remove LW2 specific code from the JIT [v2]

[Tobias Hartmann]

> The concept of flattenable fields needs some cleanup (inline types are always flattenable/null-free). We can remove the
> side-channel introduced by JDK-8212190. See JDK-8247357 for details.

Tobias Hartmann has updated the pull request incrementally with one additional commit since the last revision:

  Minor follow-up fix to handle unloaded inline klasses in C1 and correct casting of OSR inline args in C2

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Changes:
  - all: https://git.openjdk.java.net/valhalla/pull/116/files
  - new: https://git.openjdk.java.net/valhalla/pull/116/files/823daf0a..73cca1f2

Webrevs:
 - full: https://webrevs.openjdk.java.net/valhalla/116/webrev.01
 - incr: https://webrevs.openjdk.java.net/valhalla/116/webrev.00-01

  Stats: 5 lines in 4 files changed: 0 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/116.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/116/head:pull/116

PR: https://git.openjdk.java.net/valhalla/pull/116