[lworld] RFR: 8328329: [lworld] Optimize field type checking sequence for x86 target. [v2]

[Jatin Bhateja]

> - For field access bytecodes (getfield / putfield) interpreter perform special handling for flat / null restricted fields.
> - Patch replaces existing flag checking sequence with efficient sequence based on 'bt' instruction.
> 
> Kindly review and approve.
> 
> Best Regards,
> Jatin

Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:

  Refining for macrofusion.

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

Changes:
  - all: https://git.openjdk.org/valhalla/pull/1051/files
  - new: https://git.openjdk.org/valhalla/pull/1051/files/dcb3adf1..fd127e1f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1051&range=01
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1051&range=00-01

  Stats: 15 lines in 3 files changed: 0 ins; 9 del; 6 mod
  Patch: https://git.openjdk.org/valhalla/pull/1051.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1051/head:pull/1051

PR: https://git.openjdk.org/valhalla/pull/1051