[PATCH] Fix g++ 9.1 build breakage

[Tom Tromey]

>>>>> "Christian" == Christian Biesinger via gdb-patches <gdb-patches@sourceware.org> writes:

Christian> gdb/ChangeLog:
Christian> 2019-08-21  Christian Biesinger  <cbiesinger@google.com>

Christian> 	* tui/tui-data.h (tui_gen_win_info): Add an =default
Christian> 	move constructor, required by some GCC versions.

Thank you for doing this.  This is ok.

FYI we discussed this on irc and it apparently could only be reproduced
with gcc 9.1 -- I had tried gcc 8, 9.*2*, and 10.

Tom