walkProgram
walkProgramWithCfg
Fix a mistake in our (internal) types: `walkProgramWithCfg` was missing that elements can be `CfgVisitFn`. Also refactor the types for `walkProgram`, importing the original `VisitFn` and `EnterExit` types from where they're defined.
this fixes some ts-expect-errors in oxlint by generating declaration files. We could also consider using oxc_isolated_declarations to generate these