Remove unnecessary lines for hasBadMapPolyfill issue for rollup

Author: iAziz786

packages/react-reconciler/src/ReactFiber.js

@@ -101,13 +101,10 @@ if (__DEV__) {
   hasBadMapPolyfill = false;
   try {
     const nonExtensibleObject = Object.preventExtensions({});
-    const testMap = new Map([[nonExtensibleObject, null]]);
-    const testSet = new Set([nonExtensibleObject]);
-    // This is necessary for Rollup to not consider these unused.
-    // https://github.com/rollup/rollup/issues/1771
-    // TODO: we can remove these if Rollup fixes the bug.
-    testMap.set(0, 0);
-    testSet.add(0);
+    /* eslint-disable no-new */
+    new Map([[nonExtensibleObject, null]]);
+    new Set([nonExtensibleObject]);
+    /* eslint-enable no-new */
   } catch (e) {
     // TODO: Consider warning about bad polyfills
     hasBadMapPolyfill = true;

packages/react/src/BadMapPolyfill.js

@@ -12,13 +12,10 @@ if (__DEV__) {
   hasBadMapPolyfill = false;
   try {
     const frozenObject = Object.freeze({});
-    const testMap = new Map([[frozenObject, null]]);
-    const testSet = new Set([frozenObject]);
-    // This is necessary for Rollup to not consider these unused.
-    // https://github.com/rollup/rollup/issues/1771
-    // TODO: we can remove these if Rollup fixes the bug.
-    testMap.set(0, 0);
-    testSet.add(0);
+    /* eslint-disable no-new */
+    new Map([[frozenObject, null]]);
+    new Set([frozenObject]);
+    /* eslint-enable no-new */
   } catch (e) {
     // TODO: Consider warning about bad polyfills
     hasBadMapPolyfill = true;