Add 5 KSE syscalls. Two will be implemented with the next KSE

step and the others are reservations for coming code.
All will be stubbed in this kernel in the next commit.
This will allow people to easily make KSE binaries for userland testing
(the syscalls will be in libc) but they will still need a real KSE kernel
to test it. (libc looks in /sys to decide what it should add stubs for).

sys/kern/syscalls.master

@@ -547,4 +547,10 @@
 377	UNIMPL	BSD	afs_syscall
 378	STD	BSD	{ int nmount(struct iovec *iovp, unsigned int iovcnt, \
 			    int flags); }
+379	STD	BSD	{ int kse_exit(void); }
+380	STD	BSD	{ int kse_wakeup(void *); }
+381	STD	BSD	{ int kse_new(struct kse_mailbox * mbx, \
+			int new_grp_flag); }
+382	STD	BSD	{ int thread_wakeup(struct thread_mailbox *tmbx); }
+383	STD	BSD	{ int kse_yield(void); }