git: openjdk/loom: fibers: Excluded some tests with known fail reasons.

[duke]

Changeset: ae5d36c1
Author:    lmesnik <leonid.mesnik at oracle.com>
Date:      2021-02-25 13:00:49 +0000
URL:       https://git.openjdk.java.net/loom/commit/ae5d36c1

Excluded some tests with known fail reasons.

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