8l pause should generate 0xf3 0x90, not 0xf3 0x0f 0x90, which confuses the heck
out of the machine, and causes infinite loops, etc.

Reference: /n/atom/patch/applied2013/8lpause
Date: Fri Sep 27 20:38:31 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/8l/optab.c	Fri Sep 27 20:37:41 2013
+++ /sys/src/cmd/8l/optab.c	Fri Sep 27 20:37:41 2013
@@ -1027,7 +1027,7 @@
 	{ ACMPXCHGL,	yrl_ml,	Px, 0x0f,0xb1 },
 	{ ACMPXCHGW,	yrl_ml,	Pe, 0x0f,0xb1 },
 	{ ACMPXCHG8B,	yscond,	Pm, 0xc7,(01) },
-	{ APAUSE,	ynone,	Pf3, 0x90 },
+	{ APAUSE,	ynone,	Px, 0xf3,0x90 },
 
 	{ AEND },
 	0