dwarf2out.c (dw_cfi_oprnd_struct): Reduce dw_cfi_reg_num to int.

        * dwarf2out.c (dw_cfi_oprnd_struct): Reduce dw_cfi_reg_num to int.
        (lookup_cfa_1): Apply data alignment to DW_CFA_def_cfa_offset_sf
        and DW_CFA_def_cfa_sf.
        (def_cfa_1): Use DW_CFA_def_cfa_offset_sf with negative values.
        (dbx_reg_number): Don't assert particular registers here.
        (based_loc_descr): ... do it here instead.  Fold in ...
        (eliminate_reg_to_offset): ... this function.
        (compute_frame_pointer_to_cfa_displacement): Fold in the effects
        of eliminate_reg_to_offset; use FRAME_POINTER_CFA_OFFSET.
        * unwind-dw2.c (execute_cfa_program): Apply data align factor
        to DW_CFA_def_cfa_offset_sf and DW_CFA_def_cfa_sf.
        * function.c (instantiate_new_reg): Use FRAME_POINTER_CFA_OFFSET.
        (instantiate_virtual_regs): Likewise.
        * var-tracking.c (adjust_stack_reference): Likewise.
        * doc/tm.texi (FRAME_POINTER_CFA_OFFSET): New.

From-SVN: r107154