[klibc] Add faccessat() system call

Similar to access, but acts relative to a directory.
Used in util-linux.

Signed-off-by: maximilian attems <max@stro.at>
diff --git a/usr/include/unistd.h b/usr/include/unistd.h
index 0390748..f0e19c2 100644
--- a/usr/include/unistd.h
+++ b/usr/include/unistd.h
@@ -59,6 +59,7 @@
 #define F_OK	0		/* Existence */
 
 __extern int access(const char *, int);
+__extern int faccessat(int, const char *, int, int);
 __extern int link(const char *, const char *);
 __extern int linkat(int, const char *, int, const char *);
 __extern int unlink(const char *);
diff --git a/usr/klibc/SYSCALLS.def b/usr/klibc/SYSCALLS.def
index d935a92..0463df8 100644
--- a/usr/klibc/SYSCALLS.def
+++ b/usr/klibc/SYSCALLS.def
@@ -107,6 +107,7 @@
  * Inode-related system calls
  */
 int access(const char *, int);
+int faccessat(int, const char *, int, int);
 int link(const char *, const char *);
 <?> int linkat(int, const char *, int, const char *);
 int unlink(const char *);