My old friend Michael Ness is a compiler specialist and is very interested in updating the LLVM 68k project to the latest stable release as well as adding the necessary Amiga calling conventions for an Amiga version of LLVM. Currently, it is only a fork of an incomplete Classic Mac backend. Mike has just started a new job and hasn't had much time to work on it yet.
What I've discussed so far with Mike is regarding making the Clang C++ compiler link in less than 2 Gigs of RAM and eventually self-hosting. The plan that would allow such things to take place will require OOP.library from the AROS kernel to implement LibC++ and only preloading 2 passes in the optimizer. This will allow C++ class instances using a similar style of shared-library linkage to that of the BOOPSI classes used by MUI and ClassAct/ReAct for GUIs except on a slightly more abstract level.
Send me a private message with your GitHub ID and I can add you unless you'd rather start your own fork.