ok, so my proposal is:

* copy master as cortex-m-0.8x
* dump the 0.7.x/src folder and Cargo.toml file over the top of master's cortex-m/src and cortex-m/Cargo.toml, blasting away all 0.8x changes (they are still in the 0.8x branch though)
* start cherry-picking things from 0.8x into master