Missing sys/stat.h header on Solaris

[l1gi]

Hello,

on Solaris I am getting following compile errors in libcupsfilters-2.1.1:

cupsfilters/testfilters.c: In function 'test_wrapper':
cupsfilters/testfilters.c:184:68: error: 'S_IRUSR' undeclared (first use in this function)
  184 |    if ((outputfd = open(outputFile, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR)) < 0)
      |                                                                    ^~~~~~~
cupsfilters/testfilters.c:184:68: note: each undeclared identifier is reported only once for each function it appears in
cupsfilters/testfilters.c:184:78: error: 'S_IWUSR' undeclared (first use in this function)
  184 |    if ((outputfd = open(outputFile, O_WRONLY | O_CREAT | O_APPEND, S_IRUSR | S_IWUSR)) < 0)
      |                                                                              ^~~~~~~
cupsfilters/filter.c: In function 'cfFilterTee':
make[3]: *** [Makefile:1745: cupsfilters/libcupsfilters_la-testfilters.lo] Error 1
make[3]: *** Waiting for unfinished jobs....
cupsfilters/filter.c:352:48: error: 'S_IRUSR' undeclared (first use in this function)
  352 |     teefd = open(filename, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
      |                                                ^~~~~~~
cupsfilters/filter.c:352:48: note: each undeclared identifier is reported only once for each function it appears in
cupsfilters/filter.c:352:58: error: 'S_IWUSR' undeclared (first use in this function)
  352 |     teefd = open(filename, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);
      |                                                          ^~~~~~~

There is sys/stat.h include missing for S_IRUSR.

Attaching patch to fix this issue. Please, consider merging it.

Thank you,
m.

stat.h.patch