patch: init exponent for sim_fpu_class_zero

[Aldy Hernandez <aldyh@redhat.com>]

howdy.

in sim-fpu.c, the exponent is left undefined for zeros (sim_fpu_class_zero).

i am working on a port whose multiply and divide instructions check the 
value of the operands' exponent and sign to determine overflow bits to set.  
this is obviously not working when the exponent is undefined ;-).

i have verified that i can build the sim and gdb after my change (for
powerpc-eabi).

ok to install?

2002-06-09  Aldy Hernandez  <aldyh@redhat.com>

        * sim-fpu.c (unpack_fpu): Initialize exponent for
        sim_fpu_class_zero.
        (i2fpu): Same.
        (sim_fpu_sqrt): Same.

Index: sim-fpu.c
===================================================================
RCS file: /cvs/src/src/sim/common/sim-fpu.c,v
retrieving revision 1.3
diff -c -r1.3 sim-fpu.c
*** sim-fpu.c	23 Dec 2000 11:51:04 -0000	1.3
--- sim-fpu.c	11 Jun 2002 05:14:16 -0000
***************
*** 330,335 ****
--- 330,336 ----
  	  /* tastes like zero */
  	  dst->class = sim_fpu_class_zero;
  	  dst->sign = sign;
+ 	  dst->normal_exp = 0;
  	}
        else
  	{
***************
*** 520,525 ****
--- 521,527 ----
      {
        f->class = sim_fpu_class_zero;
        f->sign = 0;
+       f->normal_exp = 0;
      }
    else
      {
***************
*** 648,653 ****
--- 650,656 ----
      {
        f->class = sim_fpu_class_zero;
        f->sign = 0;
+       f->normal_exp = 0;
      }
    else
      {
***************
*** 1799,1804 ****
--- 1802,1808 ----
      {
        f->class = sim_fpu_class_zero;
        f->sign = r->sign;
+       f->normal_exp = 0;
        return 0;
      }
    if (sim_fpu_is_infinity (r))