xterm configuration breaks tmux feature

[Kyle Markley]

Hello,

I observed that in OpenBSD 7.5, the configuration of xterm is such that 
xtermcfg.h gets #define OPT_PASTE64 0.  A consequence of this is that 
OSC 52 support is compiled out, and a consequence of that is that tmux 
cannot set the primary X selection (for copying text out of a tmux pane) 
via its set-clipboard option, which uses OSC 52.

I encountered this problem as a frustrating silent failure after 
following the instructions at the tmux wiki 
(https://github.com/tmux/tmux/wiki/Clipboard).

Is there a reason that paste64 is configured out, or could we change 
this (e.g. with --enable-paste64) so that OPT_PASTE64 is 1?

--
Kyle Markley