Change section functions to be methods of dwarf2_section_info

Change section functions to be methods of dwarf2_section_info

This changes various section-related functions to be methods on
dwarf2_section_info.  I think this clarifies the role of these
functions.  This also changes one such function to return bool.

gdb/ChangeLog
2020-02-08  Tom Tromey  <tom@tromey.com>

	* dwarf2read.c (dwarf2_section_buffer_overflow_complaint)
	(dwarf2_section_size, dwarf2_get_section_info)
	(create_signatured_type_table_from_debug_names)
	(create_addrmap_from_aranges, read_debug_names_from_section)
	(get_gdb_index_contents_from_section, read_comp_unit_head)
	(error_check_comp_unit_head, read_abbrev_offset)
	(create_debug_type_hash_table, init_cu_die_reader)
	(read_cutu_die_from_dwo, dwarf2_build_psymtabs_hard)
	(read_comp_units_from_section, create_cus_hash_table)
	(create_dwp_hash_table, create_dwo_unit_in_dwp_v1)
	(create_dwp_v2_section, dwarf2_rnglists_process)
	(dwarf2_ranges_process, read_die_and_siblings, read_full_die)
	(abbrev_table_read_table, read_indirect_string_at_offset_from)
	(read_indirect_string_from_dwz, read_addr_index_1)
	(read_str_index, dwarf_decode_line_header, skip_form_bytes)
	(dwarf_decode_macro_bytes, dwarf_decode_macros)
	(fill_in_loclist_baton): Update.
	* dwarf2/section.h (struct dwarf2_section_info) <get_name,
	get_containing_section, get_bfd_owner, get_bfd_section,
	get_file_name, get_id, get_flags, empty, read>: Declare methods.
	(dwarf2_read_section, get_section_name, get_section_file_name)
	(get_containing_section, get_section_bfd_owner)
	(get_section_bfd_section, get_section_name, get_section_file_name)
	(get_section_id, get_section_flags, dwarf2_section_empty_p): Don't
	declare.
	* dwarf2/section.c (dwarf2_section_info::get_containing_section)
	(dwarf2_section_info::get_bfd_owner)
	(dwarf2_section_info::get_bfd_section)
	(dwarf2_section_info::get_name)
	(dwarf2_section_info::get_file_name, dwarf2_section_info::get_id)
	(dwarf2_section_info::get_flags, dwarf2_section_info::empty)
	(dwarf2_section_info::read): Now methods.
	* dwarf-index-write.c (class debug_names): Update.

Change-Id: Ic849f182f57a18bad6b1c7c3b9368005d307758a