test: include unstd.h in the registry test to cut down the MacOS warnings

mkdtmp, rmdir and unlink are in unstd.h on MacOS. Since including that it
doesn't hurt us on Linux, let's do it without ifdefs.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

meson.build

@@ -89,6 +89,9 @@ if get_option('default-options') != ''
 else
     configh_data.set('DEFAULT_XKB_OPTIONS', 'NULL')
 endif
+if cc.has_header('unistd.h')
+    configh_data.set('HAVE_UNISTD_H', 1)
+endif
 if cc.links('int main(){if(__builtin_expect(1<0,0)){}}', name: '__builtin_expect')
     configh_data.set('HAVE___BUILTIN_EXPECT', 1)
 endif

test/registry.c

@@ -24,6 +24,9 @@
 #include "config.h"
 
 #include <assert.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #include <stdarg.h>
 #include <stdio.h>
 #include <sys/stat.h>