* fileread.cc (File_read::~File_read): Don't delete whole_file_view_.

	* fileread.cc (File_read::~File_read): Don't delete whole_file_view_.
	(File_read::open[1]): Remove initial mapping of whole_file_view_.
	(File_read::open[2]): Add whole_file_view_ to list of views.
	(File_read::make_view): Remove test of whole_file_view_.
	(File_read::find_or_make_view): Create whole_file_view_ if
	necessary.
	(File_read::clear_views): Replace bool parameter with enum;
	adjust all callers.  Don't delete views with permanent data;
	do delete cached views and views from archives if
	--no-keep-files-mapped is set.  Set whole_file_view_ to NULL
	if clearing the corresponding view.
	* fileread.h (File_read::Clear_views_mode): New enum.
	(File_read::View::is_permanent_view): New method.
	(File_read::clear_views): Replace bool parameter
	with enum; adjust all callers.
	* options.h (General_options): Change keep_files_mapped option;
	add map_whole_files.
	* readsyms.cc (Add_symbols::run): Delete sd_ object before
	releasing the file.
	* reloc.cc (Scan_relocs::run): Delete rd_ object before releasing
	the file.