Merge branch 'polyfill-fetch' of github.com:janicklas-ralph/next.js i…

…nto polyfill-fetch

packages/next/build/webpack/plugins/build-manifest-plugin.ts

@@ -29,7 +29,7 @@ const generateClientManifest = (
   const appDependencies = new Set(assetMap.pages['/_app'])
 
   Object.entries(assetMap.pages).forEach(([page, dependencies]) => {
-    if (page === '/_app') return
+    if (page === '/_app' || page === '/_polyfills') return
     // Filter out dependencies in the _app entry, because those will have already
     // been loaded by the client prior to a navigation event
     const filteredDeps = dependencies.filter(