tests: use brfs when bundling smokehouse (#10727)

build/build-smokehouse-bundle.js

@@ -14,6 +14,7 @@ const smokehouseLibFilename = './lighthouse-cli/test/smokehouse/frontends/lib.js
 
 browserify(smokehouseLibFilename, {standalone: 'Lighthouse.Smokehouse'})
   .ignore('./lighthouse-cli/test/smokehouse/lighthouse-runners/cli.js')
+  .transform('@wardpeet/brfs', {global: true, parserOpts: {ecmaVersion: 10}})
   .bundle((err, src) => {
     if (err) throw err;
     fs.writeFileSync(bundleOutFile, src.toString());

lighthouse-cli/test/smokehouse/test-definitions/source-maps/expectations.js

@@ -7,8 +7,8 @@
 
 const fs = require('fs');
 
-const mapPath = require.resolve('../../../fixtures/source-map/script.js.map');
-const mapJson = fs.readFileSync(mapPath, 'utf-8');
+const mapJson =
+  fs.readFileSync(`${__dirname}/../../../fixtures/source-map/script.js.map`, 'utf-8');
 const map = JSON.parse(mapJson);
 
 /**