Add WASI sample

[yamachu]

No description provided.

[yamachu]

Currently the following code crashes.

Console.WriteLine($"Hello from .NET at {DateTime.Now.ToLongTimeString()}");
Console.WriteLine(await Task.FromResult(0).ContinueWith(v => v.Result, TaskScheduler.Default).ConfigureAwait(false));

and logs

Hello from .NET at 18:10:10
[wasm_trace_logger] cant resolve internal call to "System.Threading.ThreadPool::QueueCallback" (tested without signature also)

Your mono runtime and class libraries are out of sync.
The out of sync library is: /WasiConsoleApp/bin/Debug/net7.0/runtime/native/System.Private.CoreLib.dll

When you update one from git you need to update, compile and install
the other too.
Do not report this as a bug unless you're sure you have updated correctly:
you probably have a broken mono install.
If you see other errors or faults after this message they are probably related
and you need to fix your mono install first.

Task and threads does not seem to be supported now.

dotnet/runtime#65895

• Support .NET threads on threading-enabled wasm runtimes. This includes updating the synthetic-pthread.c code to support having separate pthread keys for each thread instead of a single global list.

https://github.com/yamachu/dotnet-wasi-sdk/tree/use-v7.0.0-rc1

It does not change even if rc1 is used.