DO NOT MERGE Incremental inliner

**Do not merge this PR yet**, it is obviously in a very rough state.

But now the algorithm should be complete enough that things won't change much anymore, except cleanups. So I'm posting it for the eager interested reader.
Actually I removed the (for now). We can really never inline reflective proxies, because they are not typechecked: you never know if the appropriate behavior is not supposed to be the `TypeError`. Put another way: if we call `dynamicCall` with a reflective proxy name, we cannot be sure that we found all the possible targets, because there can be non-existent possible targets.