Move Wasmtime for .NET to the Wasmtime repo.

This moves the Wasmtime for .NET implementation to the Wasmtime repo.

Wasmtime for .NET is a binding of the Wasmtime API for use in .NET.

crates/misc/dotnet/src/Imports/FunctionImport.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+
+namespace Wasmtime.Imports
+{
+    /// <summary>
+    /// Represents a function imported to a WebAssembly module.
+    /// </summary>
+    public class FunctionImport : Import
+    {
+        internal FunctionImport(IntPtr importType, IntPtr externType) : base(importType)
+        {
+            Debug.Assert(Interop.wasm_externtype_kind(externType) == Interop.wasm_externkind_t.WASM_EXTERN_FUNC);
+
+            unsafe
+            {
+                var funcType = Interop.wasm_externtype_as_functype_const(externType);
+                Parameters = Interop.ToValueKindList(Interop.wasm_functype_params(funcType));
+                Results = Interop.ToValueKindList(Interop.wasm_functype_results(funcType));
+            }
+        }
+
+        /// <summary>
+        /// The parameters of the imported function.
+        /// </summary>
+        public IReadOnlyList<ValueKind> Parameters { get; private set; }
+
+        /// <summary>
+        /// The results of the imported function.
+        /// </summary>
+        public IReadOnlyList<ValueKind> Results { get; private set; }
+    }
+}