enable LARGEFILE64 aliases

these will NOT be used when compiling with -D_LARGEFILE64_SOURCE on
musl; instead, they exist in the hopes of eventually being able to run
some glibc-linked apps with musl sitting in place of glibc.

also remove the (apparently incorrect) fcntl alias.

src/fcntl/fcntl.c

@@ -16,5 +16,3 @@ int fcntl(int fd, int cmd, ...)
 	if (cmd == F_GETOWN) return __syscall(SYS_fcntl, fd, cmd, arg);
 	return syscall(SYS_fcntl, fd, cmd, arg);
 }
-
-LFS64(fcntl);