[lworld] RFR: 8313607: [lworld] runtime/valhalla/inlinetypes/InlineOops.java GenZ assertion on aarch64

[David Simms]

Use different temp reg not related to src.index()

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Commit messages:
 - Use different temp reg not related to src.index()

Changes: https://git.openjdk.org/valhalla/pull/896/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=896&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313607
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/valhalla/pull/896.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/896/head:pull/896

PR: https://git.openjdk.org/valhalla/pull/896