Expose futureEmitAssets API (#37093)

* Expose `futureEmitAssets` API

* Fix linter

types/webpack/index.d.ts

@@ -211,6 +211,11 @@ declare namespace webpack {
         hashSalt?: string;
         /** An expression which is used to address the global object/scope in runtime code. */
         globalObject?: string;
+        /**
+         * Tells webpack to use the future version of asset emitting logic, which allows freeing memory of assets after emitting. It could break plugins which
+         * assume that assets are still readable after they were emitted.
+         */
+        futureEmitAssets?: boolean;
     }
 
     type LibraryTarget = 'var' | 'assign' | 'this' | 'window' | 'global' | 'commonjs' | 'commonjs2' | 'amd' | 'umd' | 'jsonp';