* xcoffread.c (xcoff_sym_fns): Update.

	* xcoffread.c (xcoff_sym_fns): Update.
	* symfile.h (struct sym_fns) <sym_read_psymbols>: New field.
	(enum symfile_add_flags) <SYMFILE_NO_READ>: New constant.
	* symfile.c (syms_from_objfile): Handle SYMFILE_NO_READ.
	(symbol_file_add_with_addrs_or_offsets): Likewise.
	(reread_symbols): Handle OBJF_PSYMTABS_READ.
	* somread.c (som_sym_fns): Update.
	* psymtab.h (require_partial_symbols): Declare.
	* psymtab.c (require_partial_symbols): New function.
	(ALL_OBJFILE_PSYMTABS_REQUIRED): New macro.
	(ALL_OBJFILE_PSYMTABS): Undef.
	(ALL_PSYMTABS): Move from psympriv.h.
	(lookup_partial_symtab, find_pc_sect_psymtab)
	(lookup_symbol_aux_psymtabs, relocate_psymtabs)
	(find_last_source_symtab_from_partial)
	(forget_cached_source_info_partial)
	(print_psymtab_stats_for_objfile, read_symtabs_for_function)
	(expand_partial_symbol_tables, read_psymtabs_with_filename)
	(map_symbol_names_psymtab, map_symbol_filenames_psymtab)
	(find_symbol_file_from_partial, map_matching_symbols_psymtab)
	(expand_symtabs_matching_via_partial, maintenance_info_psymtabs):
	Use ALL_OBJFILE_PSYMTABS_REQUIRED.
	* psympriv.h (ALL_PSYMTABS): Move to psymtab.c.
	* objfiles.h (OBJF_PSYMTABS_READ): New macro.
	* objfiles.c (objfile_has_partial_symbols): Handle lazily-read
	psymtabs.
	* mipsread.c (ecoff_sym_fns): Update.
	* machoread.c (macho_sym_fns): Update.
	* elfread.c (elf_symfile_read): Set up for lazy psymtab reading.
	(read_psyms): New function.
	(elf_sym_fns, elf_sym_fns_gdb_index): Update.
	(elf_sym_fns_lazy_psyms): New global.
	* dwarf2read.c (dwarf2_initialize_objfile): Don't call
	dwarf2_build_psymtabs.
	* dbxread.c (aout_sym_fns): Update.
	* coffread.c (coff_sym_fns): Update.