clear the FPillegal flag on fork. without this linuxemu is ham-strung
as it calls all syscalls from note functions (by definition).
Thus no linux procs (but the first one) can use floating point.

Thanks to cinap_lenrek for the catch.

-Steve

Notes:
Tue Sep 27 18:21:37 EDT 2011 geoff
    just applied the "& ~FPillegal";
    i don't know what procfork() is.


Reference: /n/sources/patch/applied/fp-state-on-fork
Date: Tue Sep 27 14:20:58 CES 2011
Signed-off-by: steve@quintile.net
Reviewed-by: geoff

--- /sys/src/9/port/sysproc.c	Tue Sep 27 14:17:10 2011
+++ /sys/src/9/port/sysproc.c	Tue Sep 27 14:17:05 2011
@@ -180,13 +180,16 @@
 	if((flag&RFNOTEG) == 0)
 		p->noteid = up->noteid;
 
-	p->fpstate = up->fpstate;
+	p->fpstate = up->fpstate & ~FPillegal;
 	pid = p->pid;
 	memset(p->time, 0, sizeof(p->time));
 	p->time[TReal] = MACHP(0)->ticks;
 
 	kstrdup(&p->text, up->text);
 	kstrdup(&p->user, up->user);
+
+	procfork(p);
+
 	/*
 	 *  since the bss/data segments are now shareable,
 	 *  any mmu info about this process is now stale