Isolated exec tests (#11531)

* Run exec tests in fresh contexts

* Reevaluate modules in every context

* Cache module code when running tests

* Eliminate weakmap accesses as much as possible

* Remove old multiline usage

* Using bundled polyfill to significantly increase performance

The individual requires for each file were the part that was sooooo slow.

* Drop LRU cache size

* Fixes

* Fix test

Co-authored-by: Huáng Jùnliàng <jlhwung@gmail.com>

packages/babel-plugin-transform-destructuring/test/fixtures/destructuring/array-symbol-unsupported/exec.js

@@ -1,13 +1,9 @@
 var a = (() => [1, 2, 3])();
 
 // Simulate old environment
-let _Symbol = Symbol;
-Symbol = void 0;
-try {
-  var [first, ...rest] = a;
+global.Symbol = void 0;
 
-  expect(first).toBe(1);
-  expect(rest).toEqual([2, 3]);
-} finally {
-  Symbol = _Symbol;
-}
+var [first, ...rest] = a;
+
+expect(first).toBe(1);
+expect(rest).toEqual([2, 3]);

packages/babel-plugin-transform-destructuring/test/fixtures/destructuring/non-iterable/exec.js

@@ -8,15 +8,8 @@ expect(
   () => [foo, bar] = {}
 ).toThrow(/destructure non-iterable/);
 
-// Simulate old browser
-let _Symbol = Symbol;
-Symbol = void 0;
-try {
+global.Symbol = void 0;
 
-  expect(
-    () => [foo, bar] = {}
-  ).toThrow(/destructure non-iterable/);
-
-} finally {
-  Symbol = _Symbol;
-}
+expect(
+  () => [foo, bar] = {}
+).toThrow(/destructure non-iterable/);