Add @babel/core support for the new assumptions option (#12219)

- Disallow setting assumptions to `false` in presets (#12498)

packages/babel-helper-plugin-utils/src/index.js

@@ -26,6 +26,9 @@ const apiPolyfills = {
   targets: () => () => {
     return {};
   },
+  // This is supported starting from Babel 7.13
+  // TODO(Babel 8): Remove this polyfill
+  assumption: () => () => {},
 };
 
 function copyApiObject(api) {