[lworld] RFR: 8360653: [lworld] LayoutIterationTest.java fails with -XX:ForceNonTearable=*

[Chen Liang]

Mark this test as flagless so we will skip it with any layout perturbation.

-------------

Commit messages:
 - 8360653: [lworld] LayoutIterationTest.java fails with -XX:ForceNonTearable=*

Changes: https://git.openjdk.org/valhalla/pull/1505/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1505&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8360653
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/valhalla/pull/1505.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1505/head:pull/1505

PR: https://git.openjdk.org/valhalla/pull/1505