example: concurrent instantiation per Goroutine (#1107)

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

examples/concurrent-instantiation/main_test.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/tetratelabs/wazero/internal/testing/maintester"
+	"github.com/tetratelabs/wazero/internal/testing/require"
+)
+
+// Test_main ensures the following will work:
+//
+//	go run main.go
+func Test_main(t *testing.T) {
+	stdout, _ := maintester.TestMain(t, main, "main")
+
+	for i := 0; i < 50; i++ {
+		require.True(t, strings.Contains(stdout, strconv.Itoa(i*2)))
+	}
+}