Revert moving _blockHoist after regenerator

This reverts commits 81bec3e5c4 and
157f5c3304.

test/fixtures/transformation/optional-self-contained/full/actual.js

@@ -1,6 +1,6 @@
 import foo, * as bar from "someModule";
 
 export const myWord = Symbol("abc");
-function* giveWord () {
+export function* giveWord () {
   yield myWord;
 }

test/fixtures/transformation/optional-self-contained/full/expected.js

@@ -19,6 +19,7 @@ var giveWord = _regeneratorRuntime.mark(function giveWord() {
   }, giveWord, this);
 });
 
+exports.giveWord = giveWord;
 var foo = _to5Runtime.interopRequire(require("someModule"));
 
 var bar = _to5Runtime.interopRequireWildcard(require("someModule"));