Not wanting to see this drop, I found a little time to bring the changes up to emacs master with a few notes:
1) now sits on top of a4fb5811f (Do not attempt to write .elc....)
2) The C will compile with a couple of warnings as the native comp cases are currently not handled.
3) There's dead code, commented code and other atrocities on top of the current wip
3) It segfaults during the pdumper step in the build, there is not immediately obvious reason for this, but I suspect a move or free occurs and it's not tracked
4) I have ignored the comments for large_vector and large_vector_meta for now, so the meta is kept with the vector struct.
I'm hoping now that it's a little closer to master and compiling someone might have a little more luck with the segfault issue I have been facing but I will keep try in the mean time,
JeffW