Format-neutral artifact parsing boundary and intermediate representation.
This crate owns no source-analysis dependency. Format backends turn bytes
into [ArtifactIr]; common metrics can then operate on that IR without
knowing whether it came from WebAssembly, ELF, or a later format.
Each format backend sits behind a feature of the same name, so a caller
that reads one format does not build the parsers for the others. The
archive feature turns on the four backends it delegates members to.