A trivial fix to ProblemList compiler/stable/TestUnstableStable.java with enable-preview.
------------- Commit messages: - 8377617: [lworld] ProblemList compiler/stable/TestUnstableStable.java with enable-preview Changes: https://git.openjdk.org/valhalla/pull/2076/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2076&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8377617 Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod Patch: https://git.openjdk.org/valhalla/pull/2076.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2076/head:pull/2076 PR: https://git.openjdk.org/valhalla/pull/2076
