Integrated: [bworld] Remove the old NullRestricted attribute

[Chen Liang]

This attribute has been replaced by ACC_NULL_CHECKED. Time to remove this.

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Commit messages:
 - Fix tests
 - Copyright years
 - Nuke NullRestricted attribute

Changes: https://git.openjdk.org/valhalla/pull/2067/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2067&range=00
  Stats: 983 lines in 26 files changed: 103 ins; 875 del; 5 mod
  Patch: https://git.openjdk.org/valhalla/pull/2067.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2067/head:pull/2067

PR: https://git.openjdk.org/valhalla/pull/2067