Pass context into NewRuntime (#748)

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>

examples/basic/add.go

@@ -24,7 +24,7 @@ func main() {
 	ctx := context.Background()
 
 	// Create a new WebAssembly Runtime.
-	r := wazero.NewRuntime()
+	r := wazero.NewRuntime(ctx)
 	defer r.Close(ctx) // This closes everything this Runtime created.
 
 	// Add a module to the runtime named "wasm/math" which exports one function "add", implemented in WebAssembly.