* dwarf2.h (enum dwarf_call_frame_info): Add
        DW_CFA_def_cfa_expression.
        * dwarf2out.c (union dw_cfi_oprnd_struct): Add a pointer to a
        dw_loc_descr_struct entry.
        (struct cfa_loc): New structure to track a CFA location.
        (lookup_cfa): Take a cfa_loc parameter instead of a reg and an offset.
        (lookup_cfa_1): Take a cfa_loc parameter instead of a reg and an
        offset, plus handle DW_CFA_def_cfa_expression.
        (def_cfa_1): Use to be dwarf2out_def_cfa, only now it uses a
        cfa_loc record.
        (dwarf2out_def_cfa): Entry point maintained for compatability.
        (dwarf_cfi_name): Add DW_CFA_def_cfa_expression.
        (cfa_reg, cfa_offset): Replace with cfa_loc record 'cfa'.
        (cfa_store_reg, cfa_store_offset): Replace with cfa_loc 'cfa_store'.
        (initial_return_save, dwarf2out_stack_adjust): Use cfa.reg, not
        cfa_reg.
        (dwarf2out_frame_debug_expr): Use new cfa_loc records. Recognize rtl
        sequences for the new DW_CFA_def_cfa_expression record.
        (dwarf2out_frame_debug): Use new variables/fields.A
        (output_cfi): Handle DW_CFA_def_cfa_expression.
        (output_cfa_loc): New function to generate a CFI record for
        DW_CFA_def_cfa_expression.
        (get_cfa_from_loc_descr): New function to get a cfa_loc record from
        a dw_loc_descr sequeunce.
        (build_loc_descr): Build a dw_loc_descr from a cfa_loc record.
        (dwarf_stack_op_name, new_loc_descr, add_loc_descr, size_of_loc_descr,
        size_of_locs, output_loc_operands, output_loc_sequence): Move into
        unwind info section.
        * frame.h (frame_state): Add base_offset and indirect fields.
        * frame-dwarf2.c (decode_stack_op): New function to interpret a
        dw_loc_descr operation.
        (execute_cfa_insn): Add support for DW_CFA_def_cfa_expression.
        (struct frame_state): Add base offset and indirect fields.
        * libgcc2.c (next_stack_level): Support indirect loading for CFA.

From-SVN: r34717