* mipsread.c (parse_symbol, parse_procedure): Re-do the way that

* mipsread.c (parse_symbol, parse_procedure):  Re-do the way that
.gdbinfo. symbols are created.  Move creation from parse_procedure
to parse_symbol, where it is fairly easy to grow the symtab.  This
also fixes a symtab trashing bug on all mips-based systems.
* (got_numargs, lookup_numargs, free_numargs):  Delete.  Not
needed anymore.
* tm-mips.h, tm-iris3.h, mips-tdep.c, mipsread.c:  Re-do struct
mips_extra_func_info, and all the PROC_xxx macros that look at it.