[lworld] RFR: 8355614: [lworld] SIGSEGV in InlineKlass::write_value_to_addr [v2]

[Tobias Hartmann]

> We crash in `InlineKlass::write_value_to_addr` when writing to a field that is not a flat field. The root cause is that `b->layout_kind() == LayoutKind::NULLABLE_ATOMIC_FLAT` is true in `FieldLayout::shift_fields` because `_layout_kind` contains garbage. It needs to be initialized in the constructor.
> 
> I also fixed a few other minor things.
> 
> Thanks,
> Tobias

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

  Reverted changes in fieldInfo.hpp

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1472/files
  - new: https://git.openjdk.org/valhalla/pull/1472/files/5343fd4e..49b7251c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1472&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1472&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/valhalla/pull/1472.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1472/head:pull/1472

PR: https://git.openjdk.org/valhalla/pull/1472