the original C implementation was derived directly from cloudabi-utils.
that implementation is no longer in tree.
acfoltzer's initial Rust implementation included a path_open function
that was ported from cloudabi-utils. this rewrite of wasi-common has
completely delegated all path lookup functionality to cap-std (in the
cap-std-sync impls), and cap-std itself has a completely re-designed
method of path resolution.
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