Always allow preview class files, compile standard libs with --enable-preview
------------- Commit messages: - Always allow preview class files, compile standard libs with --enable-preview Changes: https://git.openjdk.org/valhalla/pull/2037/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=2037&range=00 Stats: 17 lines in 7 files changed: 5 ins; 0 del; 12 mod Patch: https://git.openjdk.org/valhalla/pull/2037.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/2037/head:pull/2037 PR: https://git.openjdk.org/valhalla/pull/2037
