module: fix #16476 extension lookups for top main

Author: guybedford

lib/module.js

@@ -435,7 +435,7 @@ Module._load = function(request, parent, isMain) {
           ESMLoader.hook(hooks);
         }
       }
-      await ESMLoader.import(getURLFromFilePath(request).href);
+      await ESMLoader.import(getURLFromFilePath(request).pathname);
     })()
     .catch((e) => {
       console.error(e);

test/parallel/test-module-main-extension-lookup.js

@@ -0,0 +1,7 @@
+'use strict';
+require('../common');
+const { execFileSync } = require('child_process');
+
+const node = process.argv[0];
+
+execFileSync(node, ['--experimental-modules', 'test/es-module/test-esm-ok']);