git: openjdk/loom: fibers: Clarify which tests fail due to using nsk.share.MainWrapper, and therefore are not vthread specific.

[duke]

Changeset: 3ba8537b
Author:    Chris Plummer <chris.plummer at oracle.com>
Date:      2021-12-09 17:02:15 +0000
URL:       https://git.openjdk.java.net/loom/commit/3ba8537b5a18a5ea63ffdeee3e5a982436451143

Clarify which tests fail due to using nsk.share.MainWrapper, and therefore are not vthread specific.

! test/hotspot/jtreg/ProblemList-vthread.txt