[RFA] mips-tdep.c: Set mips_default_saved_regsize to 8 for N32

[Kevin Buettner <kevinb@redhat.com>]

For the N32 ABI, registers are 64 bits wide, and all 64-bits are
sometimes used for certain data types (e.g. when passing structs). 
So, when a register is saved in a function prologue, it is necessary
to save all 64 bits of the register.  I've verified this by looking at
some function prologues created by SGI's compiler; the "sd" (which
saves the entire 64-bit register) instruction is used to save
registers.

With this change in place, the following FAILs are fixed for n32:

FAIL: gdb.base/call-ar-st.exp: print print_small_structs, pattern 1
FAIL: gdb.base/call-ar-st.exp: print print_ten_doubles, pattern 5 + sentinel
FAIL: gdb.base/call-ar-st.exp: print print_small_structs from print_long_arg_list, pattern 1
FAIL: gdb.base/call-ar-st.exp: print print_bit_flags_combo from init_bit_flags_combo
FAIL: gdb.base/call-ar-st.exp: print print_long_arg_list, pattern 7
FAIL: gdb.base/call-ar-st.exp: print sum_struct_print(10, *struct1, *struct2, *struct3, *struct4)
FAIL: gdb.base/call-ar-st.exp: print print_struct_rep(*struct1, *struct2, *struct3), pattern 2
FAIL: gdb.base/call-ar-st.exp: print print_one_large_struct(*list1)

Okay to commit?

	* mips-tdep.c (mips_gdbarch_init): For the N32 ABI, set
	mips_default_saved_regsize to 8.

Index: mips-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/mips-tdep.c,v
retrieving revision 1.85
diff -u -p -r1.85 mips-tdep.c
--- mips-tdep.c	31 Jul 2002 20:26:49 -0000	1.85
+++ mips-tdep.c	31 Jul 2002 22:34:59 -0000
@@ -4480,7 +4480,7 @@ mips_gdbarch_init (struct gdbarch_info i
       set_gdbarch_long_long_bit (gdbarch, 64);
       break;
     case MIPS_ABI_N32:
-      tdep->mips_default_saved_regsize = 4;
+      tdep->mips_default_saved_regsize = 8;
       tdep->mips_default_stack_argsize = 8;
       tdep->mips_fp_register_double = 1;
       tdep->mips_last_arg_regnum = A0_REGNUM + 8 - 1;