Add syscall stubs to get through libpthread initializers

pk/syscall.c

@@ -455,6 +455,8 @@ long do_syscall(long a0, long a1, long a2, long a3, long a4, long a5, unsigned l
     [SYS_getrlimit] = sys_stub_nosys,
     [SYS_setrlimit] = sys_stub_nosys,
     [SYS_chdir] = sys_chdir,
+    [SYS_set_tid_address] = sys_stub_nosys,
+    [SYS_set_robust_list] = sys_stub_nosys,
   };
 
   const static void* old_syscall_table[] = {

pk/syscall.h

@@ -49,6 +49,8 @@
 #define SYS_setrlimit 164
 #define SYS_getrusage 165
 #define SYS_clock_gettime 113
+#define SYS_set_tid_address 96
+#define SYS_set_robust_list 99
 
 #define OLD_SYSCALL_THRESHOLD 1024
 #define SYS_open 1024