What to call the latest pypy3.8 release?

I broke C-ABI compatibility with the latest 7.3.6 release of PyPy. Also 
this is hard to talk about since we have python3.7 and pypy7.3.6 (soon 
to be pypy7.3.7).

For 3.7 (probably the last fully supported release, only security and 
large bug fixes planned), I will back out the C-ABI breakage so that 
existing pp37-pypy73 binary wheels will continue working and make a 
7.3.7 release, see the abi-compat branch.

I am not sure how to progress with the python3.8 branch, under the 
assumption that there will not be another 3.7 release. On the one hand, 
purists would argue "we changed the ABI, we need to increment the 
version to 7.4.0". On the other hand, since this is the first release of 
python3.8, the wheel tag will become pp38-pypy73 which is unambiguous, 
so we could just leave the pypy version 7.3.x until we break ABI 
compatibility with 7.3.6.

Opinions? We should decide soon since packagers will begin releasing 
wheels/distros soon.

Matti