Question for vec_set: I don't see any change on vec_set patten, also I am not aware vec_set can set a sub-vector since the standard pattern name only having one mode `vec_setm`, I thought that means it implied we can only set scalar/element mode into specific field?
Also what's the best way to test this patch? Will those patterns be generated by expander or generated during IRA/LRA? If so, could you provide a few testcase within the patch?
