stubdom: add stub functions to reduce qemu patches

diff -r fda7bb635f7e extras/mini-os/include/posix/fcntl.h
@@ -0,0 +1,11 @@
+#ifndef _POSIX_FCNTL_H
+#define _POSIX_FCNTL_H
+
+#include_next <fcntl.h>
+
+#define F_ULOCK 0
+#define F_LOCK  1
+#define F_TLOCK 2
+#define F_TEST  3
+
+#endif /* _POSIX_FCNTL_H */

diff -r fda7bb635f7e extras/mini-os/lib/sys.c
@@ -1186,6 +1186,7 @@
 /* Not supported by FS yet.  */
 unsupported_function_crash(link);
 unsupported_function(int, readlink, -1);
+unsupported_function_crash(umask);
 
 /* We could support that.  */
 unsupported_function_log(int, chdir, -1);

@@ -1208,6 +1209,13 @@
 unsupported_function(int, sigaltstack, -1);
 unsupported_function_crash(kill);
 
+/* Unsupported */
+unsupported_function_crash(pipe);
+unsupported_function_crash(fork);
+unsupported_function_crash(execv);
+unsupported_function_crash(waitpid);
+unsupported_function_crash(lockf);
+unsupported_function_crash(sysconf);
 unsupported_function(int, tcsetattr, -1);
 unsupported_function(int, tcgetattr, 0);

diff -r fda7bb635f7e extras/mini-os/include/posix/fcntl.h
@@ -0,0 +1,11 @@
+#ifndef _POSIX_FCNTL_H
+#define _POSIX_FCNTL_H
+
+#include_next <fcntl.h>
+
+#define F_ULOCK 0
+#define F_LOCK  1
+#define F_TLOCK 2
+#define F_TEST  3
+
+#endif /* _POSIX_FCNTL_H */

diff -r 9afe01a0e160 extras/mini-os/lib/sys.c
@@ -1185,6 +1185,7 @@
 /* Not supported by FS yet.  */
 unsupported_function_crash(link);
 unsupported_function(int, readlink, -1);
+unsupported_function_crash(umask);
 
 /* We could support that.  */
 unsupported_function_log(int, chdir, -1);

@@ -1207,6 +1208,16 @@
 unsupported_function(int, sigaltstack, -1);
 unsupported_function_crash(kill);
 
+/* Unsupported */
+unsupported_function_crash(pipe);
+unsupported_function_crash(fork);
+unsupported_function_crash(execv);
+unsupported_function_crash(waitpid);
+unsupported_function_crash(lockf);
+unsupported_function_crash(sysconf);
+unsupported_function(int, tcsetattr, -1);
+unsupported_function(int, tcgetattr, 0);
+
 /* Linuxish abi for the Caml runtime, don't support */
 unsupported_function_log(struct dirent *, readdir64, NULL);
 unsupported_function_log(int, getrusage, -1);