* fhandler_registry.cc (perf_data_files): New table.

	* fhandler_registry.cc (perf_data_files): New table.
	(PERF_DATA_FILE_COUNT): New constant.
	(fhandler_registry::exists): Add check for HKEY_PERFORMANCE_DATA
	value names.
	(fhandler_registry::fstat): For HKEY_PERFORMANCE_DATA, return
	default values only.
	(fhandler_registry::readdir): For HKEY_PERFORMANCE_DATA, list
	names from perf_data_files only.
	(fhandler_registry::fill_filebuf): Use larger buffer to speed up
	access to HKEY_PERFORMANCE_DATA values.  Remove check for possible
	subkey.  Add RegCloseKey ().
	(open_key): Replace goto by break, remove label.  Do not try to
	open subkey of HKEY_PERFORMANCE_DATA.  Add missing RegCloseKey ()
	after open subkey error.