add missing STAB_TYPE_CODE

[Dale Johannesen]

When generating stabs for a parameter passed on the stack by
invisible reference, the STAB_TYPE_CODE (current_sym_code)
is never set.  This fixes it; our gdb guy confirms N_PSYM is
the right value.  Bootstrapped and tested on Darwin.

Index: dbxout.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/dbxout.c,v
retrieving revision 1.125
diff -u -d -b -w -c -3 -p -r1.125 dbxout.c
cvs server: conflicting specifications of output style
*** dbxout.c    13 Sep 2002 23:29:56 -0000      1.125
--- dbxout.c    23 Sep 2002 17:48:24 -0000
*************** dbxout_parms (parms)
*** 2681,2686 ****
--- 2681,2687 ----
               current_sym_value
                 = INTVAL (XEXP (XEXP (XEXP (DECL_RTL (parms), 0), 0), 
1));
             current_sym_addr = 0;
+           current_sym_code = N_PSYM;

             FORCE_TEXT;
             fprintf (asmfile, "%s\"%s:v", ASM_STABS_OP, decl_name);