traverse: port scope.push API from Babel #5049
Description
Babel's implementation is here
Why need this API?
We need to combine the variable declarators required by different plugins to be inserted at the top of the statements.
Related tests:
- logical-assignment/null-coalescing/input.js
-var _obj$x, _obj$x2, _deep$obj, _deep$obj$x, _deep$obj2, _deep$obj2$x, _key, _obj$_key, _key2, _obj$_key2, _deep$obj3, _key3, _deep$obj3$_key, _deep$obj4, _key4, _deep$obj4$_key;
+var _obj$x, _obj$x2, _deep$obj$x, _deep$obj2$x, _obj$_key, _obj$_key2, _deep$obj3$_key, _deep$obj4$_key;
+var _deep$obj, _deep$obj2, _key, _key2, _deep$obj3, _key3, _deep$obj4, _key4;