[lworld] RFR: 8289686: [lworld] Unnecessary buffering because constant getters with scalarized arg are not C2 compiled

[Tobias Hartmann]

The fix for [JDK-8275825](https://bugs.openjdk.org/browse/JDK-8275825) is incomplete. Getter methods returning a nullable inline type in scalarized form are still treated as trivial and therefore not C2 compiled which leads to buffering. Also, constant getter methods with an (unused) scalarized inline type receiver/argument should not be treated as trivial.

Thanks to @kuksenko for reporting!

Best regards,
Tobias

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Commit messages:
 - 8289686: [lworld] Unnecessary buffering because constant getters with scalarized arg are not C2 compiled

Changes: https://git.openjdk.org/valhalla/pull/719/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=719&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289686
  Stats: 94 lines in 3 files changed: 87 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/valhalla/pull/719.diff
  Fetch: git fetch https://git.openjdk.org/valhalla pull/719/head:pull/719

PR: https://git.openjdk.org/valhalla/pull/719