[frv sim] clip cut point for MWCUT

[DJ Delorie <dj@redhat.com>]

The MWCUT opcode only looks at the six LSBs of the cut point register.
The frv.c code was looking at the whole register, resulting in
incorrect cut results.  This patch clips the cut_point argument to six
bits (0..63).  Ok to apply?

	* frv/frv.c (frvbf_cut): Only look at the six LSBs of
	cut_point.

Index: frv.c
===================================================================
RCS file: /cvs/src/src/sim/frv/frv.c,v
retrieving revision 1.9
diff -p -U3 -r1.9 frv.c
--- frv.c	24 Aug 2007 14:28:36 -0000	1.9
+++ frv.c	18 Dec 2007 21:42:50 -0000
@@ -1055,6 +1055,7 @@ SI
 frvbf_cut (SIM_CPU *current_cpu, SI reg1, SI reg2, SI cut_point)
 {
   SI result;
+  cut_point &= 0x3f;
   if (cut_point < 32)
     {
       result = reg1 << cut_point;