How do I get the start of `(x+y).bit_length()` in 
`total += (x+y).bit_length()`?
With your change, I can't get it from `x`, `x+y`, or from the whole statement.

The primary purpose of the locations are for tracebacks, not for static tools.
Also, most tools need to support earlier versions of Python and consistency between versions is the most important thing.

A third-party parser that supported full, accurate locations would be great, but I don't think the builtin parser is the place for it.