Parse import-assertions (#12139)

Co-authored-by: Huáng Jùnliàng <jlhwung@gmail.com>
Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

packages/babel-plugin-syntax-import-assertions/src/index.js

@@ -0,0 +1,13 @@
+import { declare } from "@babel/helper-plugin-utils";
+
+export default declare(api => {
+  api.assertVersion(7);
+
+  return {
+    name: "syntax-import-assertions",
+
+    manipulateOptions(opts, parserOpts) {
+      parserOpts.plugins.push(["importAssertions"]);
+    },
+  };
+});