Add back debug-test utility

Author: NullVoxPopuli

tests/helpers/debug-test.js

@@ -0,0 +1,16 @@
+import { DEBUG } from '@glimmer/env';
+import { test } from 'qunit';
+
+export default function debugTest(description, callback) {
+  return test(description, function (assert) {
+    if (!DEBUG) {
+      assert.pushResult({
+        result: true,
+        message: 'debug functions are disabled',
+      });
+      return;
+    }
+
+    return callback.apply(this, arguments);
+  });
+}