+ Added optional multiple **process corner** technology lef support (min/max/nom), in addition to the already existing multiple **timing corner** support (ss/tt/ff). This will also be our nomenclature going fwd.
+ Parasitics extraction now run at all process corners, and multi-corner analysis is run at all three process corners
~ `finishing` -> `signoff`
~ Parasitics extraction and STA are now an independent step instead of being lumped in routing, as part of the signoff block
~ Update OpenROAD
~ Update Open_PDKs, Sky130, and Magic
~ PDK verification made more PDK agnostic outside of env.py
~ Made RCX use LEF files instead of multiple configuration variables/set_rc.tcl
~ `prep_lefs` more or less rewritten
- Removed redundant RCX variables
- Removed `-order_wires` from various `read_def`s in OpenROAD- deprecated, apparently
The best thing to happen to OpenLane since OpenLane.
Variables related to output files: i.e. logs, results and reports, are becoming more uniform.
* Variables now point to folders
* Variables now called `{stage}_{type}s`
* All variables renamed to be tool-generic
* magic, klayout, cvc and lvs all unified, renamed "finishing"
* Better flow runtime calculation
* All step runtimes are now stored in a yaml file, which can easily be read by a human or parsed by a computer.
* Better step indexing
* You have to increment the step index explicitly using `increment_index`.
* Functions that take log arguments now require you to not use an indexed file, it's their responsibility to index them.
* Changed names for many logs to make more sense
* A plethora of files being moved and/or renamed
* Yosys scripts were moved into their own folder
* All references to OpenLANE that are not a published paper have been replaced with OpenLane
* Copyright dates updated on some files
