0.14.1 differs from 0.14.0 primarily in that the GNU/Linux build is
built on Ubuntu 16.04 instead of 18.04, meaning we'll use an earlier
version of GLIBC.
Allows for ergonomic swapping out of stdin, stdout, stderr as well as
a new PreopenDir sub-builder which enables for user control over the
permissions that the directory is preopened with.
This PR includes breaking changes to the pubilc API.
In strict mode, `get_wasi_version` uses the previous behavior, i.e. it
checks that there is only one namespace for all imports, and that this
namespace is a WASI namespace (and uses it to find the WASI version).
In non-strict mode, `get_wasi_version` checks that at least one WASI
namespace exists (and uses it to find the WASI version).
By default, `is_wasi_module` uses the non-strict mode.
In addition to `Snapshot0` and `Snapshot1`, I believe it is an
interesting API to provide the `Latest` version, so that the user can
write:
```rust
generate_import_object_for_version(WasiVersion::Latest, …);
```
This is a way to ensure that modules will run only if they come with
the latest WASI version (in case of security issues for instance), by
just updating the runtime.
Note that it can be dangerous if not used carefully, but we assume the
user knows what it does by sticking on a specific “floating” version.
Also note that the `Latest` version is never returned by any API. It
is provided only by the user.
If a module has multiple import namespaces, `get_wasi_version` is
broken because it assumes a module must only have a single namespace.
This patch fixes it by a slower `get_wasi_version` function, but a
correct one. As soon as the `wasi_unstable` or
`wasi_snapshot_preview1` namespace is met, `get_wasi_version` maps it
to the respective `WasiVersion` variant. It assumes however that a
module must hold a unique WASI version.
