testing.B.Loop() standardization and StackAsync.Debug improvement (#156)

* testing.B.Loop() standardization and StackAsync.Debug heap debugging improvement

* apply @MDr164 fixes

* @MDr164 great suggestions to prevent panic and print correct mallocs

x/xnet/xnet_untinygo_test.go

@@ -13,6 +13,9 @@ import (
 )
 
 func TestTinyGoTest(t *testing.T) {
+	if testing.Short() {
+		t.Skip("`tinygo test` skipped on short test")
+	}
 	if exec.Command("tinygo", "version").Run() != nil {
 		t.Skip("tinygo not installed")
 	}