[lworld] RFR: 8374093: [lworld] Cleanup and polish around vgetfield/vputfield

[Joel Sikström]

Hello,

I've been looking at the new internal bytecodes vgetfield and vputfield and their callchains from the interpreter down to InlineKlass and have some cleanups. I've not looked at templateTable_x86 so far, only templateTable_aarch64.

Some notes:
* The `dest_is_initialized` parameter in InlineKlass::write_value_to_addr is `true` for all callers, so I've removed it and inlined `true` to the call to `copy_payload_to_addr`.
* There seems to be an unnecessary `mark_payload_as_non_null((address)src);` in InlineKlass::copy_payload_to_addr, as the payload should already be non_null if it doesn't match `is_payload_marked_as_null` in the if-statement just above.

Testing:
* hotspot_valhalla, jdk_valhalla and tier1

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

Commit messages:
 - 8374093: [lworld] Cleanup and polish around vgetfield/vputfield

Changes: https://git.openjdk.org/valhalla/pull/1840/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1840&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8374093
  Stats: 35 lines in 10 files changed: 0 ins; 4 del; 31 mod
  Patch: https://git.openjdk.org/valhalla/pull/1840.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1840/head:pull/1840

PR: https://git.openjdk.org/valhalla/pull/1840