meson vs. llvm bitcode files

The meson build currently does not produce llvm bitcode (.bc) files. 
AFAIK, this is the last major regression for using meson for production 
builds.

Is anyone working on that?  I vaguely recall that some in-progress code 
was shared a couple of years ago, but I haven't seen anything since.  It 
would be great if we could collect any existing code and notes to maybe 
get this moving again.