evolve: fix creation of prunedchildren for merge The `p2` code path was broken. (stupid typo)

evolve: add a debugobsstorestat command This commands print multiple some data about the content of the obsstore. This will be usefull to provide some metric and insight for obsolescence marker exchange.

evolve: extend obsstore object to use prune parent information Now that we have the information, we can use it to build a mapping to access all marker that prune a children of a node. This is similar to what we do for successors and precursors. The performance impact is a few tens of second on my mercurial clone. Experimenting is worth the trouble.

prune: wrap mercurial internal to add parent information in prune marker We store as a p1 (and p2) key in the extra dict for marker. This allow us to record this information for future use without requiering a format change.

evolve: drop `latercomer` and `conflicting` compatibility. Those old alias are deprecated for a long time now. All computations related to troubles are in Mercurial core for multiple versions.

test: get rid of all reference to conflicting changesets They are now called divergent for a long time.

evolve: use flag value from core for bumped fix This flag is available from core for a long time, lets use it directly from there. This commit intend to cleanup old stuff from the evolve extention.

importing fastop extension in this repo This repo is dedicated to experimentation on mutable history topic. Fastop is appropriate there.

fastobs: revset refactor related fixes

adapt fastopt extension to mercurial.exchange module The push code have changed to be more modular. the fastop extension need to be rewritten. No backward compatibility preserved for mercurial <=2.9x.

drop unused function `pushmarkerwrapper` I can find any user for this function.

Add initial test.

Deduplicate markers. Depends on __hash__ and __eq__ on obsolete.marker

copy precursor revset from evolve so we don't depend on involve