* dwarf2read.c (dwarf2_per_objfile): New member quick_file_names_table.

	* dwarf2read.c (dwarf2_per_objfile): New member quick_file_names_table.
	(dwarf2_per_cu_quick_data): Move definition down to "quick functions"
	section.  Delete members lines full_names.  Rename read_lines to
	no_file_data.
	(quick_file_names): New struct.
	(hash_file_name_entry, eq_file_name_entry): New functions.
	(delete_file_name_entry, create_quick_file_names_table): New functions.
	(dwarf2_read_index): Initialize quick_file_names_table.
	(dw2_get_file_names): Renamed from dw2_require_line_header.
	Return pointer to quick_file_names entry.  All callers updated.
	(dw2_get_real_path): Renamed from dw2_require_full_path.
	Replace per_cu arg with pointer to quick_file_names entry.
	All callers updated.
	(dw2_free_cached_file_names): New function.
	(dw2_forget_cached_source_info): Call it (via htab_traverse_noresize).
	(dwarf2_initialize_objfile): Initialize quick_file_names_table in
	the OBJF_READNOW case.
	(dwarf2_free_objfile): Rewrite freeing of quick file names tables.