Build error on Haiku

[Begasus]

With the latest release I ran into a build error (was trying to look into solvespace that's using mimalloc, so far haven't come up with a sollution. :)

In file included from /Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/prim.c:22:
/Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/unix/prim.c: In function 'mi_prim_open':
/Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/unix/prim.c:82:10: warning: implicit declaration of function 'open' [-Wimplicit-function-declaration]
   82 |   return open(fpath,open_flags);
      |          ^~~~
In file included from /boot/system/develop/headers/os/storage/StorageDefs.h:9,
                 from /boot/system/develop/headers/os/kernel/OS.h:15,
                 from /Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/unix/prim.c:597,
                 from /Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/prim.c:22:
/boot/system/develop/headers/posix/fcntl.h: At top level:
/boot/system/develop/headers/posix/fcntl.h:94:17: error: conflicting types for 'open'; have 'int(const char *, int, ...)'
   94 | extern int      open(const char *path, int openMode, ...);
      |                 ^~~~
/boot/system/develop/headers/posix/fcntl.h:94:1: note: a parameter list with an ellipsis cannot match an empty parameter name list declaration
   94 | extern int      open(const char *path, int openMode, ...);
      | ^~~~~~
In file included from /Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/prim.c:22:
/Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/unix/prim.c:82:10: note: previous implicit declaration of 'open' with type 'int()'
   82 |   return open(fpath,open_flags);
      |          ^~~~
/Opslag/wip/solvespace-3.1/extlib/mimalloc/src/prim/unix/prim.c:90:12: warning: 'mi_prim_access' defined but not used [-Wunused-function]
   90 | static int mi_prim_access(const char *fpath, int mode) {
      |            ^~~~~~~~~~~~~~
extlib/mimalloc/CMakeFiles/mimalloc-static.dir/build.make:271: recipe for target 'extlib/mimalloc/CMakeFiles/mimalloc-static.dir/src/prim/prim.c.o' failed

Pokes @Jessica-Koch