test: add preload and prefetch tests

Author: FogelAI

test/cases/prefetch-preload-mixed/a.js

@@ -0,0 +1,2 @@
+import(/* webpackPrefetch: true, webpackChunkName: "a1" */ "./a1");
+import(/* webpackPrefetch: true, webpackChunkName: "a2" */ "./a2");

test/cases/prefetch-preload-mixed/a1.js

@@ -0,0 +1,3 @@
+import(/* webpackPrefetch: true, webpackChunkName: "b1" */ "./b1");
+import(/* webpackPreload: true, webpackChunkName: "b2" */ "./b2");
+import(/* webpackPrefetch: true, webpackChunkName: "b3" */ "./b3");

test/cases/prefetch-preload-mixed/a2.js

@@ -0,0 +1,2 @@
+import(/* webpackPreload: true, webpackChunkName: "c1" */ "./c1");
+import(/* webpackPreload: true, webpackChunkName: "c2" */ "./c2");