MFC r302669,302677-302686,303761,304602,304603,305027-305028,305259,
305710,305711,308067-308070,308178,308179,308230,308553,309338,309526,
343125 (by cem): Synchronize ioat(4) with head.
Most of these changes are 3 years old, just never got merged.