* dwarf2out.c (dw_cfi_oprnd_struct, dw_fde_struct, add_fde_cfi,
        reg_save, dwarf2out_frame_debug_expr, dwarf2out_def_cfa,
        dwarf2out_window_save, dwarf2out_args_size, dwarf2out_reg_save,
        dwarf2out_return_save, dwarf2out_return_reg,
        dwarf2out_stack_adjust, dwarf2out_frame_debug, primary_filename,
        add_AT_lbl_id, add_AT_lbl_offset, type_tag, decl_start_label,
        gen_compile_unit_die, dwarf2out_init): Constify a char*.

        * dwarf2out.h (dwarf2out_init): Likewise.

        * dwarfout.c (filename_entry, primary_filename, last_filename,
        type_tag, output_compile_unit_die, dwarfout_init): Likewise.

        * tree.h (dwarf2out_def_cfa, dwarf2out_window_save,
        dwarf2out_args_size, dwarf2out_reg_save, dwarf2out_return_save,
        dwarf2out_return_reg): Likewise.

From-SVN: r33448