git: openjdk/amber: super-init: Use @enablePreview in tests in preference to explicit command line flags.

[duke]

Changeset: 353defb9
Author:    Archie L. Cobbs <archie.cobbs at gmail.com>
Date:      2023-05-16 21:26:42 +0000
URL:       https://git.openjdk.org/amber/commit/353defb9ab24d7bd22821dfb6a9f257ba7922535

Use @enablePreview in tests in preference to explicit command line flags.

! test/langtools/tools/javac/SuperInit/SuperInitFails.java
! test/langtools/tools/javac/SuperInit/SuperInitGood.java