merge security fixes for xkb, as found in these xserver gitlab
commits:

270e439739e023463e7e0719a4eede69d45f7a3f - xkb: only swap once in XkbSetMap
446ff2d3177087b8173fa779fa5b77a2a128988b - Check SetMap request length carefully
87c64fc5b0db9f62f4e361444f4b60501ebf67b9 - Fix XkbSetDeviceInfo() and SetDeviceIndicators() heap overflows
de940e06f8733d87bbb857aef85d830053442cfe - xkb: fix key type index check in _XkbSetMapChecks
f7cd1276bbd4fe3a9700096dec33b52b8440788d - Correct bounds checking in XkbSetNames()

i haven't tested these run OK, and it was a 33 out of 34 hunks
did not apply cleanly, but they merge was still largely the
same (patch failed due to whitespace changes mostly), and i am
able to build-test successfully.

initial import of existing netbsd xorg-server 1.10 sources in the
xorg-server.old subdir.