btc: Switch to the util library.
btc: Switch to the util library.

Former-commit-id: e4322f4e8a867dca9948afa2b6f410e9eb812202 [formerly ff802662cc458b691363e0e4cd31688816ee76d4]
Former-commit-id: 60379c9e46e004c2e1681dddebf9b7f26d233105
torhve/ivar2,torhve/ivar2,torhve/ivar2,haste/ivar2