Snippets for graphicsmagick 1.3.48 from Alpine riscv64

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-riscv64/community/graphicsmagick/graphicsmagick-1.3.48-r0.log.

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

• coders/url.c:203:11: warning: 'xmlNanoHTTPOpen' is deprecated [-Wdeprecated-declarations]
    203 |           context=xmlNanoHTTPOpen(filename,&type);
        |           ^~~~~~~
  

• coders/url.c:206:15: warning: 'xmlNanoHTTPRead' is deprecated [-Wdeprecated-declarations]
    206 |               while ((bytes=xmlNanoHTTPRead(context,buffer,MaxBufferExtent)) > 0)
        |               ^~~~~
  

• coders/url.c:208:15: warning: 'xmlNanoHTTPClose' is deprecated [-Wdeprecated-declarations]
    208 |               xmlNanoHTTPClose(context);
        |               ^~~~~~~~~~~~~~~~
  

• coders/url.c:210:15: warning: 'xmlNanoHTTPCleanup' is deprecated [-Wdeprecated-declarations]
    210 |               xmlNanoHTTPCleanup();
        |               ^~~~~~~~~~~~~~~~~~