[jdk17u-dev] RFR: 8305959: x86: Improve itable_stub

[Dmitry Chuyko]

This is a performance backport from 21. Original patch was applied mostly cleanly. Few bits required slight tuning. 

Straightforward replacements were made in in macroAssembler_x86.cpp because of missing JDK-8308396 refactoring (21):
in_bytes(itableMethodEntry::method_offset()) to itableMethodEntry::method_offset_in_bytes(),
in_bytes(itableOffsetEntry::interface_offset()) to itableOffsetEntry::interface_offset_in_bytes(),
in_bytes(itableOffsetEntry::offset_offset()) to itableOffsetEntry::offset_offset_in_bytes().

One java import hunk was manually redone in the benchmark class.

Testing: linux x86 tier1,2; the benchmark shows improvements similar to original results.

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Commit messages:
 - Backport 8cdd95e8a2a7814ab7983fb3f41e6fa5793d410f

Changes: https://git.openjdk.org/jdk17u-dev/pull/2654/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2654&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8305959
  Stats: 295 lines in 5 files changed: 250 ins; 24 del; 21 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2654.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2654/head:pull/2654

PR: https://git.openjdk.org/jdk17u-dev/pull/2654