const compress/flate.matchOffsetOnlyMask

3 uses

	compress/flate (current package)
		huffman_bit_writer.go#L925: 			bits |= uint64((offset-(offsetComb>>8))&matchOffsetOnlyMask) << (nbits & 63)
		token.go#L21: 	matchOffsetOnlyMask = 0xffff
		token.go#L167: 		t.AddMatch(uint32(tok.length()), tok.offset()&matchOffsetOnlyMask)