refactor(es/minifier): Respect top-level when invoking IIFE (#7690)

Author: Austaras

crates/swc/tests/fixture/issues-2xxx/2679/output/index.js

@@ -1,4 +1,2 @@
-!function() {
-    var a = {};
-    a.b = 1, a = null, window.test = a;
-}();
+var a;
+(a = {}).b = 1, a = null, window.test = a;

crates/swc/tests/fixture/issues-3xxx/3126/1/output/index.js

@@ -1,17 +1,14 @@
-!function() {
-    __webpack_require__.m = {
-        746: function(__unused_webpack_module, __unused_webpack___webpack_exports__, __webpack_require__1) {
-            Object.prototype.hasOwnProperty;
-        }
-    }, __webpack_require__.O = function(result, chunkIds, fn, priority) {
-        for(var j = 0; j < chunkIds.length; j++)Object.keys(__webpack_require__.O).every(function(key) {
-            return __webpack_require__.O[key](chunkIds[j]);
-        });
-    };
-    var __webpack_exports__ = __webpack_require__.O(void 0, [
-        532
-    ], function() {
-        return __webpack_require__(746);
+var __webpack_exports__;
+__webpack_require__.m = {
+    746: function(__unused_webpack_module, __unused_webpack___webpack_exports__, __webpack_require__1) {
+        Object.prototype.hasOwnProperty;
+    }
+}, __webpack_require__.O = function(result, chunkIds, fn, priority) {
+    for(var j = 0; j < chunkIds.length; j++)Object.keys(__webpack_require__.O).every(function(key) {
+        return __webpack_require__.O[key](chunkIds[j]);
     });
-    __webpack_exports__ = __webpack_require__.O(__webpack_exports__);
-}();
+}, __webpack_exports__ = __webpack_require__.O(void 0, [
+    532
+], function() {
+    return __webpack_require__(746);
+}), __webpack_exports__ = __webpack_require__.O(__webpack_exports__);