[binutils patch] DWARF-5: Extend bfd/dwarf2.c parse_comp_unit()

[binutils patch] DWARF-5: Extend bfd/dwarf2.c parse_comp_unit()

bfd/
2017-07-04  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* dwarf2.c (struct dwarf2_debug): Add fields dwarf_line_str_buffer and
	dwarf_line_str_size.
	(struct attr_abbrev): Add field implicit_const.
	(dwarf_debug_sections): Add .debug_line_str.
	(enum dwarf_debug_section_enum): Add debug_line_str and debug_max.
	(dwarf_debug_section_assert): Add static assertion.
	(read_indirect_line_string): New.
	(read_abbrevs): Support DW_FORM_implicit_const.
	(is_str_attr): Support DW_FORM_line_strp.
	(read_attribute_value): Support DW_FORM_line_strp and
	DW_FORM_implicit_const.
	(read_attribute): Support DW_FORM_implicit_const.
	(line_info_add_include_dir, line_info_add_include_dir_stub):
	(line_info_add_file_name, read_formatted_entries): New.
	(decode_line_info, parse_comp_unit): Support DWARF 5.
	(_bfd_dwarf2_cleanup_debug_info): Free dwarf_line_str_buffer.