Currently, this is identical to the `wasm32-wasi` in all but name. See #449 for
the next step, which is to incrementally add Preview 2 features,
e.g. `wasi-sockets`. Per the discussion in that PR, I've split the
`wasi-sysroot/include` directory into per-target directories. Eventually, we'll
want to build a separate sysroot for each target, but there's currently
uncertainty about how to configure the default sysroot for e.g. clang, so we're
not tackling that yet.
See also #447 for further details.
Signed-off-by: Joel Dice <joel.dice@fermyon.com>