RFR: JDK-8301050: Detect Xen Virtualization on Linux aarch64 [v3]

[Matthias Baesken]

> With https://bugs.openjdk.org/browse/JDK-8300266 KVM and VMWare virtualization detection has been added; this should be enhanced by Xen detection.
> However it seems that for Xen we should look at other file system locations compared to the other virtualizations.
> more /sys/hypervisor/type
> xen
> seems to be available there.

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  Move more coding into check_info_file

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/12217/files
  - new: https://git.openjdk.org/jdk/pull/12217/files/3ef5c503..f4175a91

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=12217&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=12217&range=01-02

  Stats: 22 lines in 2 files changed: 5 ins; 9 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/12217.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/12217/head:pull/12217

PR: https://git.openjdk.org/jdk/pull/12217