Split @babel/runtime into two separate runtime modules.

packages/babel-runtime-corejs2/helpers/temporalRef.js

@@ -0,0 +1,11 @@
+var temporalUndefined = require("./temporalUndefined");
+
+function _temporalRef(val, name) {
+  if (val === temporalUndefined) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}
+
+module.exports = _temporalRef;