[lworld] RFR: 8336842: [lworld] Return value buffering in TLAB does not work with -XX:FastAllocateSizeLimit=0

[Tobias Hartmann]

We fail with `-XX:FastAllocateSizeLimit=0` because `Klass::_lh_instance_slow_path_bit` is set in the layout helper which is then used as object size for TLAB allocations in `MacroAssembler::store_inline_type_fields_to_buf`. The fix is to add the corresponding check.

I'll add testing with `-XX:FastAllocateSizeLimit=0` to our (internal) stress job.

Best regards,
Tobias

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Commit messages:
 - 8336842: [lworld] Return value buffering in TLAB does not work with -XX:FastAllocateSizeLimit=0

Changes: https://git.openjdk.org/valhalla/pull/1207/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1207&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8336842
  Stats: 16 lines in 2 files changed: 6 ins; 2 del; 8 mod
  Patch: https://git.openjdk.org/valhalla/pull/1207.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1207/head:pull/1207

PR: https://git.openjdk.org/valhalla/pull/1207