merge libSM 1.2.4, and libXxf86dga 1.1.6

initial import of libXxf86dga-1.1.6

Fix "no output of xdpyinfo(1) on redirect or pipe" problem.

XF86cleanup() in libXxf86dga invoked via atexit(3)
(or __attribute__((__destructor__)) in NetBSD xsrc)
calls _exit(2) directly so fflush(3) via normal exit(3)
is not called. Analyzed by rin@, ryo@, and soda@:
https://mail-index.netbsd.org/tech-x11/2021/01/20/msg002192.html

Should be pulled up to netbsd-9.

XXX1: The original XF86cleanup() is not async-signale-safe.
XXX2: XF86DGAGetVideo() implicitly overrides signal handlers.

merge libXvMC 1.0.11, libXxf86dga 1.1.5, libxkbfile 1.1.0, and xtrans 1.4.0.

initial import of libXxf86dga-1.1.5

use a destructor instead of atexit(3) to prevent SEGV's after dlclose.

initial import of libXxf86dga-1.1.4

initial import of libXxf86dga-1.1.2

merge libXxf86dga 1.1.1

initial import of libXxf86dga-1.1.1

initial import of libXxf86dga-1.0.2