This patch adds the assembly/disassembly for the following instructions:
sqcvtn : Signed saturating extract narrow and interleave
sqcvtun : Signed saturating unsigned extract narrow and interleave
uqcvtn : Unsigned saturating extract narrow and interleave
The reference can be found here:
https://developer.arm.com/documentation/ddi0602/2022-09
Do you mind exposing tsz8_64 at this level to match sve2_int_sat_extract_narrow...? I know we only need one size right now but structurally this will make it easier to update in the future. You can still have multiclass sve2p1_multi_vec_extract_narrow that uses this minimalist interface, again much like how sve2_int_sat_extract_narrow_bottom works. We'll need the multiclass anyway once we start enabling code generation.