bundle2: load hookargs from bundleoperation into transaction when started one When a transaction is started, we must load the hookargs from the bundleoperation object to the transaction so that they can be used in the transaction. Also this patch makes sure no more hookargs are added to the bundleoperation object once the transaction starts. This is a part of porting fb extension bundle2hooks to core. Differential Revision: https://phab.mercurial-scm.org/D209

bundle2: add the capability to store hookargs on bundle operation object There are extensions like pushrebase, pushvars which run hooks on a server before taking the lock. Since the lock is not taken, transaction is not there, so the hookargs can't be stored on the transaction. Adding hooksargs to bundle operation object will help in running hooks before taking the lock. This is a part of moving fb's extension bundle2hooks to core. Differential Revision: https://phab.mercurial-scm.org/D208

rebase: use one dirstateguard for when using rebase.singletransaction This was previously landed as 2519994d25ca but backed out in b63351f6a2 because it broke hooks mid-rebase and caused conflict resolution data loss in the event of unexpected exceptions. This new version adds the behavior back but behind a config flag, since the performance improvement is notable in large repositories. The old commit message was: Recently we switched rebases to run the entire rebase inside a single transaction, which dramatically improved the speed of rebases in repos with large working copies. Let's also move the dirstate into a single dirstateguard to get the same benefits. This let's us avoid serializing the dirstate after each commit. In a large repo, rebasing 27 commits is sped up by about 20%. I believe the test changes are because us touching the dirstate gave the transaction something to actually rollback. (grafted from 9e3dc3a1638b9754b58a0cb26aaa75d868058109) (grafted from 7d38b41d2266d9a02a15c64229fae0da5738dcec) Differential Revision: https://phab.mercurial-scm.org/D135