RFR: 8317415: [lworld] Preload_attribute needs moving to jdk.internal.classfile.attribute

[Vicente Romero]

mostly a merge issue

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Commit messages:
 - 8317415: [lworld] Preload_attribute needs moving to jdk.internal.classfile.attribute

Changes: https://git.openjdk.org/valhalla/pull/1008/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1008&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8317415
  Stats: 7 lines in 2 files changed: 0 ins; 7 del; 0 mod
  Patch: https://git.openjdk.org/valhalla/pull/1008.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1008/head:pull/1008

PR: https://git.openjdk.org/valhalla/pull/1008