pango, socat, libXfixes: upgraded package to upstream

Upgraded x11-libs/pango to version 1.54.0.
Upgraded x11-libs/libXfixes to version 6.0.2.
Upgraded net-misc/socat to version 1.8.1.0.

Introduced xorg-meson.eclass to support the uprev.

BUG=b:476113242
TEST=CQ

Change-Id: I2ca9fe76859c4340388edcdd2a27c08ee56ce06e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/7507485
Commit-Queue: Zihan Chen <zihanchen@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: maciek swiech <drmasquatch@google.com>
Tested-by: Zihan Chen <zihanchen@google.com>
11 files changed