Fix tdz checks in transform-block-scoping plugin (#9498)

* Better tdz tests

- Use jest's expect.toThrow/expect.not.toThrow
- Add input/output tests

* Fix basic tdz (a = 2; let a)

Fixes #6848

* Make _guessExecutionStatusRelativeTo more robust

* Add tests

* Return less "unkown" execution status

* "function" execution status does not exist

* Fix recursive functions

* Update helper version

* "finally" blocks are always executed

* Typo

packages/babel-plugin-transform-block-scoping/test/fixtures/exec/scope-bindings.js

@@ -5,6 +5,7 @@ if (x) {
 
 var innerScope = true;
 var res = transform(code, {
+  configFile: false,
   plugins: opts.plugins.concat([
     function (b) {
       var t = b.types;
@@ -34,3 +35,4 @@ if (x) {
 }`;
 
 expect(res.code).toBe(expected);
+expect(innerScope).toBe(false);