The `portarcs` pass was already ignoring `$buf` cells when loading
timing data, but now bufnorm will also emit `$input_port` and `$connect`
helper cells, which need to be ignored as well.
Rename passes/cmds from "General passes" to "Design modification".
More `yosys.h` includes.
cmdref: Split passes/status from passes/cmds
Rename passes/cmds from "General passes" to "Design modification".
More `yosys.h` includes.