misc/59543: Build fails on Linux host

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         59543
>Category:       misc
>Synopsis:       Build fails on Linux host
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    misc-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jul 22 10:15:00 +0000 2025
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date 2025.07.22.04.45.13
>Organization:
  
>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

Building NetBSD-current on a Debian 12 host now fails.  See log output at:

  https://www.gson.org/netbsd/bugs/build/amd64-baremetal/
  https://www.gson.org/netbsd/bugs/build/macppc/

The latest error is:

  /dev/shm/build/2025.07.22.04.45.13-amd64-baremetal/xsrc/external/mit/fontconfig/dist/src/fccache.c: In function 'FcDirCacheMapHelper':
  /dev/shm/build/2025.07.22.04.45.13-amd64-baremetal/xsrc/external/mit/fontconfig/dist/src/fccache.c:1076:10: warning: implicit declaration of function 'timercmp'; did you mean 'memcmp'? [-Wimplicit-function-declaration]
   1076 |     if (!timercmp (&zero_mtime, &dir_mtime, !=))
        |          ^~~~~~~~
        |          memcmp

>How-To-Repeat:

>Fix: