RFR: 8376046: [lworld] Adjust @NullRestricted tests to remove @Strict

[Chen Liang]

PR 3 in the series. Massive search and replace to replace all usage of `@Strict` and `@NullRestricted` with just `@NullRestricted`. Requires both #1951 and #1952.

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Depends on: https://git.openjdk.org/valhalla/pull/1952

Commit messages:
 - Redundancy in dummy source
 - Merge branch 'test/strict-out' into test/remove-strict
 - Remove @Strict where @NullRestricted is present

Changes: https://git.openjdk.org/valhalla/pull/1959/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1959&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8376046
  Stats: 514 lines in 104 files changed: 0 ins; 462 del; 52 mod
  Patch: https://git.openjdk.org/valhalla/pull/1959.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1959/head:pull/1959

PR: https://git.openjdk.org/valhalla/pull/1959