[lworld] Integrated: 8293523: test/langtools/tools/javac/preview/PreviewTest is failing after the merge with 'master'

[Vicente Romero]

just restoring a missing piece of code in the compiler for test `test/langtools/tools/javac/preview/PreviewTest` to pass

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Commit messages:
 - 8293523: test/langtools/tools/javac/preview/PreviewTest is failing after the merge with

Changes: https://git.openjdk.org/valhalla/pull/748/files
 Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=748&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8293523
  Stats: 4 lines in 1 file changed: 4 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/valhalla/pull/748.diff
  Fetch: git fetch https://git.openjdk.org/valhalla pull/748/head:pull/748

PR: https://git.openjdk.org/valhalla/pull/748