introduce monitor and mwait to amd64 port.  we still lack a type
to mwait on.

Reference: /n/atom/patch/applied2013/fsmonmwait
Date: Tue Sep 17 21:22:41 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/fs/amd64/squid.c	Tue Sep 17 21:22:13 2013
+++ /sys/src/fs/amd64/squid.c	Tue Sep 17 21:22:13 2013
@@ -34,7 +34,7 @@
 	 */
 	DBG("Wait for the thunderbirds!\n");
 	while(!active.thunderbirdsarego)
-		;
+		monmwait(&active.thunderbirdsarego, 0);
 	wrmsr(0x10, sys->epoch);
 	m->rdtsc = rdtsc();
 
--- /sys/src/fs/amd64/fns.h	Tue Sep 17 21:22:13 2013
+++ /sys/src/fs/amd64/fns.h	Tue Sep 17 21:22:13 2013
@@ -28,7 +28,7 @@
 void	hardhalt(void);
 void	i8042a20(void);
 void	i8042reset(void);
-void	idle(void);
+#define	idlehands()	monmwait(&runq.head, 0)		/* can't be fn due to runq being proc.c private */
 void	idthandlers(void);
 void	idtput(int, u64int);
 int	inb(int);
--- /sys/src/fs/port/proc.c	Tue Sep 17 21:22:13 2013
+++ /sys/src/fs/port/proc.c	Tue Sep 17 21:22:13 2013
@@ -158,8 +158,8 @@
 	User *p;
 
 	for (;;) {
-		while(runq.head == nil)		/* if nobody to run, */
-			idle();			/* idle with intrs enabled */
+		while(runq.head == nil)
+			idlehands();
 		splhi();
 		lock(&runq);
 		p = runq.head;
--- /sys/src/fs/pc/l.s	Tue Sep 17 21:22:13 2013
+++ /sys/src/fs/pc/l.s	Tue Sep 17 21:22:13 2013
@@ -649,7 +649,7 @@
 /*
  *  do nothing whatsoever till interrupt happens
  */
-TEXT	idle(SB),$0
+TEXT	idlehands(SB),$0
 	HLT
 	RET
 
--- /sys/src/fs/pc/fns.h	Tue Sep 17 21:22:13 2013
+++ /sys/src/fs/pc/fns.h	Tue Sep 17 21:22:13 2013
@@ -20,8 +20,8 @@
 int	getfields(char*, char**, int, int, char*);
 void	i8042a20(void);
 void	i8042reset(void);
-#define	halthi()	idle()
-void	idle(void);
+#define	halthi()	idlehands()
+void	idlehands(void);
 int	inb(int);
 ulong	inl(int);
 void	insb(int, void*, int);