Fix start_all_threads in libos-kern
In I inadvertently removed __other_thread_start,
which is the entry point for new threads.
This isn't really tested by anything currently, but I modified hello.c to ensure it
linked and started without crashing.
@@ -36,3 +36,12 @@ do_main: call main
call call_atexit_functions
call exit
+
+ # Called from schedule.c
+ .globl __other_thread_start
+__other_thread_start:
+ # Load global pointer
+ movehi gp, hi(_GLOBAL_OFFSET_TABLE_)
+ or gp, gp, lo(_GLOBAL_OFFSET_TABLE_)
+ call worker_thread
+ call thread_exit
