Snippets for xfe 2.1.7 from Alpine armv7

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-armv7/community/xfe/xfe-2.1.7-r0.log.

• /usr/include/sys/signal.h:1:2: warning: #warning redirecting incorrect #include <sys/signal.h> to <signal.h> [-Wcpp]
      1 | #warning redirecting incorrect #include <sys/signal.h> to <signal.h>
        |  ^~~~~~~