int32 and int64 compatibility merging in f054e84f761734905e22c464034076f2ffb46a50, 25535e35a86c7b226882f70d8e0a924f8661fa35m, 7e81098011029750eac78d64f9d53034a53693bc, 0ec36a25a231c827c20a7cf194b1f99b7336d529 from golang/protobuf this also reverts some changes made in 86d28beb3f2bc5fe92a519b7231379e587399470 in gogo/protobuf