fix io.Bytebuffer.Read for new EOF semantics
fix io.Bytebuffer.Read for new EOF semantics

R=rsc
DELTA=7  (5 added, 0 deleted, 2 changed)
OCL=30657
CL=30659

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go