message: go: fix unknown field 'UOffset' to 'Pos'
diff: @@ -1251,9 +1251,9 @@ func CheckVtableDeduplication(fail func(string, ...interface{})) {
  len(want), want, len(got), got)
  }
  - table0 := &flatbuffers.Table{Bytes: b.Bytes, UOffset: flatbuffers.UOffsetT(len(b.Bytes)) - obj0}
  - table1 := &flatbuffers.Table{Bytes: b.Bytes, UOffset: flatbuffers.UOffsetT(len(b.Bytes)) - obj1}
  - table2 := &flatbuffers.Table{Bytes: b.Bytes, UOffset: flatbuffers.UOffsetT(len(b.Bytes)) - obj2}
  + table0 := &flatbuffers.Table{Bytes: b.Bytes, Pos: flatbuffers.UOffsetT(len(b.Bytes)) - obj0}
  + table1 := &flatbuffers.Table{Bytes: b.Bytes, Pos: flatbuffers.UOffsetT(len(b.Bytes)) - obj1}
  + table2 := &flatbuffers.Table{Bytes: b.Bytes, Pos: flatbuffers.UOffsetT(len(b.Bytes)) - obj2}
  testTable := func(tab *flatbuffers.Table, a flatbuffers.VOffsetT, b, c, d byte) {
  // vtable size
  