* autoload.cc (two_addr_t): Use __uint64_t as type for the i686
	version, analogue to __uint128_t for x86_64.
	(INIT_WRAPPER): New x86_64 macro to install a sysv_abi function wrapper
	for the DLL init functions.  Add long comment to explain why this is
	necessary.  Create wrapper for std_dll_init and wsock_init.
	(std_dll_init): Rename with leading underscore on x86_64 and take
	calling function as argument.  Disable overwriting return address on
	stack for x86_64.
	(wsock_init): Ditto.