Merge #11389: Support having SegWit always active in regtest (sipa, ajtowns, jnewbery)
d61845818 Have SegWit active by default (Pieter Wuille)
4bd89210a Unit tests for always-active versionbits. (Anthony Towns)
d07ee77ab Always-active versionbits support (Pieter Wuille)
18e071841 [consensus] Pin P2SH activation to block 173805 on mainnet (John Newbery)
526023aa7 Improve handling of BIP9Deployment limits (Anthony Towns)
Pull request description:
Most tests shouldn't have to deal with the now-historical SegWit activation transition (and other deployments, but SegWit is certainly the hardest one to accomodate).
This PR makes a versionbits starttime of -1 equal to "always active", and enables it by default for SegWit on regtest. Individual tests can override this by using the existing `-vbparams` option.
A few unit tests and functional tests are adapted to indeed override vbparams, as they specifically test the transition.
This is in preparation for wallet SegWit support, but I thought having earlier eyes on it would be useful.
Tree-SHA512: 3f07a7b41cf46476e6c7a5c43244e68c9f41d223482cedaa4c02a3a7b7cd0e90cbd06b84a1f3704620559636a2268f5767d4c52d09c1b354945737046f618fe5