fix building on alpine w/ musl

src/fs_copy_file_range_linux.icpp

@@ -22,6 +22,7 @@
 
 #include "errno.hpp"
 
+#include <fcntl.h>
 #include <stdio.h>
 #include <sys/syscall.h>
 #include <sys/types.h>

src/xattr.hpp

@@ -25,7 +25,8 @@
 #endif
 
 #ifdef USE_XATTR
-# ifdef __GLIBC__
+# ifdef __linux__
+#  include <sys/types.h>
 #  include <sys/xattr.h>
 # else
 #  undef USE_XATTR