I'd like to raise your attention again to the ext_vector_type boolean patch (https://reviews.llvm.org/D88905). We've fully addressed the last round of technical feedback and expect this to be good to go.
After rsmith's remarks, we have switched to ext_vector_type attribute for bool vectors in C/C++ (instead of vector_size bool).
The patch has been idling for the last few weeks without feedback and it's not clear to me whether there are any technical and/or conceptual reservations or whether this could go ahead. I'd appreciate, if you could have a look at the patch: