(Hevc/xIT): Merging IT4x4 into IT_Merger.
(Hevc/xIT): Merging IT8x8 into IT_Merger.
(Hevc/xIT): Merging IT16x16 into IT_Merger.
(Hevc/xIT): merging invDST4x4 and IT32x32 into IT_Merger.