add failing utf16 surrogate pair test
add failing utf16 surrogate pair test

SAGV/buffer,beni55/buffer,jessetane/buffer,kawanet/buffer,mafintosh/buffer,SAGV/buffer,LinusU/buffer,loon3/buffer,btd/buffer,loon3/buffer,LinusU/buffer,beni55/buffer,nolanlawson/buffer,btd/buffer,feross/buffer,LiuDeng/buffer,feross/buffer,kawanet/buffer,feross/buffer,nolanlawson/buffer,mafintosh/buffer,LiuDeng/buffer