* autoload.cc (LoadDLLprime): Change dllname storage to string16.

	* autoload.cc (LoadDLLprime): Change dllname storage to string16.
	(struct dll_info): Convert name to WCHAR.
	(std_dll_init): Load DLLs with full path to windows system directory.
	Add hint to Microsoft security advisory.
	* dcrt0.cc (init_windows_system_directory): New function.
	(dll_crt0_0): Call init_windows_system_directory first.
	* exceptions.cc (windows_system_directory): Move to globals.cc.
	(windows_system_directory_length): Ditto.
	(events_init): Drop code fetching windows_system_directory.
	* globals.cc (windows_system_directory): New global variable.
	(windows_system_directory_length): Ditto.
	* net.cc (load_ipv6_funcs): Use windows_system_directory rather than
	GetSystemDirectoryW.
	* netdb.cc (open_system_file): Ditto.  Simplify debug output.