Add detection for OmniOS (Solaris variant)

[bram-perl]

Reference: https://omnios.org/

It's currently reported as:

$ perl -Ilib -MSystem::Info -wle 'my $x = System::Info->new(); print $x->os();'
Solaris - 2.11

which isn't really correct..

$ perl -wle 'print $^O';
solaris

$ uname -a
SunOS bram-omnios 5.11 omnios-r151042-2a01bcc289 i86pc i386 i86pc

$ find /etc -type f -iname '*release*'
/etc/os-release
/etc/release

$ cat /etc/release
  OmniOS v11 r151042
  Copyright (c) 2012-2017 OmniTI Computer Consulting, Inc.
  Copyright (c) 2017-2022 OmniOS Community Edition (OmniOSce) Association.
  All rights reserved. Use is subject to licence terms.

(that leading whitespace is in the file)

$ cat /etc/os-release
NAME="OmniOS"
PRETTY_NAME="OmniOS Community Edition v11 r151042"
CPE_NAME="cpe:/o:omniosce:omnios:11:151042:0"
ID=omnios
VERSION=r151042
VERSION_ID=r151042
BUILD_ID=151042.0.2022.04.26
HOME_URL="https://omnios.org/"
SUPPORT_URL="https://omnios.org/"
BUG_REPORT_URL="https://github.com/omniosorg/omnios-build/issues/new"

$ psrinfo -v
Status of virtual processor 0 as of: 09/02/2022 22:53:24
  on-line since 09/02/2022 22:32:34.
  The i386 processor operates at 1200 MHz,
        and has an i387 compatible floating point processor.

$ ls -ld /usr/platform
drwxr-xr-x   3 root     sys            3 Apr 30 08:20 /usr/platform
$ ls -l /usr/sbin/sizer
/usr/sbin/sizer: No such file or directory

$ uname -i
i86pc
$ ls -l /usr/platform/i86pc/sbin/prtdiag
/usr/platform/i86pc/sbin/prtdiag: No such file or directory
$ find / -name 'prtdiag'
/usr/sbin/prtdiag
$ /usr/sbin/prtdiag
System Configuration: innotek GmbH VirtualBox
BIOS Configuration: innotek GmbH VirtualBox 12/01/2006

==== Processor Sockets ====================================

Version                          Location Tag
-------------------------------- --------------------------

==== Memory Device Sockets ================================

Type        Status Set Device Locator      Bank Locator
----------- ------ --- ------------------- ----------------

==== On-Board Devices =====================================

==== Upgradeable Slots ====================================

ID  Status    Type             Description
--- --------- ---------------- ----------------------------

[bram-perl]

$ perl t/etc/get-lsb.pl
cat > os-release <<EOFV
NAME="OmniOS"
PRETTY_NAME="OmniOS Community Edition v11 r151042"
CPE_NAME="cpe:/o:omniosce:omnios:11:151042:0"
ID=omnios
VERSION=r151042
VERSION_ID=r151042
BUILD_ID=151042.0.2022.04.26
HOME_URL="https://omnios.org/"
SUPPORT_URL="https://omnios.org/"
BUG_REPORT_URL="https://github.com/omniosorg/omnios-build/issues/new"
EOFV
cat > release <<EOFV
  OmniOS v11 r151042
  Copyright (c) 2012-2017 OmniTI Computer Consulting, Inc.
  Copyright (c) 2017-2022 OmniOS Community Edition (OmniOSce) Association.
  All rights reserved. Use is subject to licence terms.
EOFV